Hot Days, Warm Nights and Frost Days by Decade
How often hot days, warm nights, frost days and ice days occur by decade since the 1960s worldwide, from a fixed set of up to 2,481 stations. Built from NOAA GHCN-Daily station records by this site; every chart states its stations and its period.
Data as of . Last revised (2026-10-17).
Key Facts
- Worldwide, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 2,481 stations rose from 48.5 to 54.6 between the 1960s and the 2010s; the 2020s so far (6 years) average 57.0.
- Worldwide, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 2,481 stations rose from 10.4 to 13.1 between the 1960s and the 2010s; the 2020s so far (6 years) average 14.2.
- Worldwide, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 2,481 stations rose from 1.0 to 1.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 1.8.
- Worldwide, the mean number of warm nights, with a daily minimum at or above 20 C (68 F) per year at 2,304 stations rose from 20.3 to 28.3 between the 1960s and the 2010s; the 2020s so far (6 years) average 28.6.
- Worldwide, the mean number of frost days, with a daily minimum at or below 0 C (32 F) per year at 2,304 stations fell from 117.7 to 107.0 between the 1960s and the 2010s; the 2020s so far (6 years) average 103.1.
- Worldwide, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 2,481 stations fell from 35.4 to 31.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 26.0.
- Each code uses its own fixed set of stations, the same in every decade from the 1960s, so the change comes from the same places.
- The same measures are on this page for 4 continents and 17 countries.
How to Read This Page
Each chart counts days in a year that cross a temperature line: a daily maximum at or above 30 C (86 F), 35 C (95 F) or 40 C (104 F); a warm night, when the daily minimum stays at or above 20 C (68 F); a frost day, when the daily minimum is 0 C (32 F) or lower; and an ice day, when even the daily maximum is 0 C (32 F) or lower. Each bar is the mean number of such days per year in one decade.
The station set is fixed for each measure. A station is in the set only when it has at least 6 complete years in every decade from the 1960s to the 2010s and at least 3 in the 2020s, so the same places are compared decade after decade and a change in which stations report cannot move the bars. A year is complete when all 12 months have at least 20 days of both the daily maximum and the daily minimum. A measure appears for a scope only when at least 10 stations are in its set. The 2020s are not over, so that bar covers only the complete years so far.
Stations are not spread evenly: some regions have many and others few, so a continent or world figure describes the stations in the set and not every place. Every figure here describes what the station records show. It does not say why it changed. Stations that do not have enough complete years in every decade are left out, which favours long running stations in well covered countries.
This page has the world, 4 continents and 17 countries with data. Each scope has its own station sets, named in its charts.
Hot Days, Warm Nights and Frost Days by Decade: World
Up to 2,481 stations per measure, fixed sets- Worldwide, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 2,481 stations rose from 48.5 to 54.6 between the 1960s and the 2010s; the 2020s so far (6 years) average 57.0.
- Worldwide, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 2,481 stations rose from 10.4 to 13.1 between the 1960s and the 2010s; the 2020s so far (6 years) average 14.2.
- Worldwide, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 2,481 stations rose from 1.0 to 1.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 1.8.
- Worldwide, the mean number of warm nights, with a daily minimum at or above 20 C (68 F) per year at 2,304 stations rose from 20.3 to 28.3 between the 1960s and the 2010s; the 2020s so far (6 years) average 28.6.
- Worldwide, the mean number of frost days, with a daily minimum at or below 0 C (32 F) per year at 2,304 stations fell from 117.7 to 107.0 between the 1960s and the 2010s; the 2020s so far (6 years) average 103.1.
- Worldwide, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 2,481 stations fell from 35.4 to 31.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 26.0.
Days at or above 30 C
| Decade | Mean days per year |
|---|---|
| 1960s | 48.5 |
| 1970s | 48.6 |
| 1980s | 50.3 |
| 1990s | 48.2 |
| 2000s | 51.0 |
| 2010s | 54.6 |
| 2020s (so far, 6 years) | 57.0 |
Days at or above 35 C
| Decade | Mean days per year |
|---|---|
| 1960s | 10.4 |
| 1970s | 10.1 |
| 1980s | 12.2 |
| 1990s | 10.7 |
| 2000s | 11.9 |
| 2010s | 13.1 |
| 2020s (so far, 6 years) | 14.2 |
Days at or above 40 C
| Decade | Mean days per year |
|---|---|
| 1960s | 1.0 |
| 1970s | 1.0 |
| 1980s | 1.3 |
| 1990s | 1.1 |
| 2000s | 1.3 |
| 2010s | 1.5 |
| 2020s (so far, 6 years) | 1.8 |
Tropical nights (min at or above 20 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 20.3 |
| 1970s | 21.2 |
| 1980s | 23.3 |
| 1990s | 23.7 |
| 2000s | 24.8 |
| 2010s | 28.3 |
| 2020s (so far, 6 years) | 28.6 |
Frost days (min at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 117.7 |
| 1970s | 115.9 |
| 1980s | 113.5 |
| 1990s | 108.8 |
| 2000s | 108.4 |
| 2010s | 107.0 |
| 2020s (so far, 6 years) | 103.1 |
Ice days (max at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 35.4 |
| 1970s | 34.7 |
| 1980s | 33.7 |
| 1990s | 30.2 |
| 2000s | 30.4 |
| 2010s | 31.5 |
| 2020s (so far, 6 years) | 26.0 |
Each measure counts days in complete years only. A station is in a measure's set when it has complete years in every decade from the 1960s, so each chart compares the same places over time. A grey bar is a decade that is not over.
All climate measures for World
Hot Days, Warm Nights and Frost Days by Decade: Asia
Up to 103 stations per measure, fixed sets- In Asia, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 103 stations rose from 58.9 to 68.6 between the 1960s and the 2010s; the 2020s so far (6 years) average 76.1.
- In Asia, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 103 stations rose from 12.8 to 19.8 between the 1960s and the 2010s; the 2020s so far (6 years) average 22.6.
- In Asia, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 103 stations rose from 1.0 to 2.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 2.5.
- In Asia, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 103 stations fell from 41.0 to 35.9 between the 1960s and the 2010s; the 2020s so far (6 years) average 30.5.
Days at or above 30 C
| Decade | Mean days per year |
|---|---|
| 1960s | 58.9 |
| 1970s | 57.5 |
| 1980s | 57.6 |
| 1990s | 60.9 |
| 2000s | 65.9 |
| 2010s | 68.6 |
| 2020s (so far, 6 years) | 76.1 |
Days at or above 35 C
| Decade | Mean days per year |
|---|---|
| 1960s | 12.8 |
| 1970s | 12.7 |
| 1980s | 13.3 |
| 1990s | 15.1 |
| 2000s | 16.5 |
| 2010s | 19.8 |
| 2020s (so far, 6 years) | 22.6 |
Days at or above 40 C
| Decade | Mean days per year |
|---|---|
| 1960s | 1.0 |
| 1970s | 1.2 |
| 1980s | 1.4 |
| 1990s | 1.4 |
| 2000s | 1.4 |
| 2010s | 2.5 |
| 2020s (so far, 6 years) | 2.5 |
Ice days (max at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 41.0 |
| 1970s | 41.7 |
| 1980s | 41.3 |
| 1990s | 37.4 |
| 2000s | 35.5 |
| 2010s | 35.9 |
| 2020s (so far, 6 years) | 30.5 |
Each measure counts days in complete years only. A station is in a measure's set when it has complete years in every decade from the 1960s, so each chart compares the same places over time. A grey bar is a decade that is not over.
Hot Days, Warm Nights and Frost Days by Decade: Europe
Up to 590 stations per measure, fixed sets- In Europe, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 590 stations rose from 6.8 to 13.3 between the 1960s and the 2010s; the 2020s so far (6 years) average 14.8.
- In Europe, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 590 stations rose from 0.8 to 2.2 between the 1960s and the 2010s; the 2020s so far (6 years) average 2.9.
- In Europe, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 590 stations rose from 0.0 to 0.1 between the 1960s and the 2010s; the 2020s so far (6 years) average 0.2.
- In Europe, the mean number of warm nights, with a daily minimum at or above 20 C (68 F) per year at 571 stations rose from 2.0 to 4.7 between the 1960s and the 2010s; the 2020s so far (6 years) average 5.6.
- In Europe, the mean number of frost days, with a daily minimum at or below 0 C (32 F) per year at 571 stations fell from 110.1 to 92.8 between the 1960s and the 2010s; the 2020s so far (6 years) average 85.0.
- In Europe, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 590 stations fell from 47.5 to 34.8 between the 1960s and the 2010s; the 2020s so far (6 years) average 27.4.
Days at or above 30 C
| Decade | Mean days per year |
|---|---|
| 1960s | 6.8 |
| 1970s | 6.2 |
| 1980s | 7.2 |
| 1990s | 9.2 |
| 2000s | 11.0 |
| 2010s | 13.3 |
| 2020s (so far, 6 years) | 14.8 |
Days at or above 35 C
| Decade | Mean days per year |
|---|---|
| 1960s | 0.8 |
| 1970s | 0.6 |
| 1980s | 1.0 |
| 1990s | 1.2 |
| 2000s | 1.7 |
| 2010s | 2.2 |
| 2020s (so far, 6 years) | 2.9 |
Days at or above 40 C
| Decade | Mean days per year |
|---|---|
| 1960s | 0.0 |
| 1970s | 0.0 |
| 1980s | 0.1 |
| 1990s | 0.1 |
| 2000s | 0.1 |
| 2010s | 0.1 |
| 2020s (so far, 6 years) | 0.2 |
Tropical nights (min at or above 20 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 2.0 |
| 1970s | 1.9 |
| 1980s | 2.5 |
| 1990s | 3.3 |
| 2000s | 3.9 |
| 2010s | 4.7 |
| 2020s (so far, 6 years) | 5.6 |
Frost days (min at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 110.1 |
| 1970s | 106.6 |
| 1980s | 106.1 |
| 1990s | 98.8 |
| 2000s | 94.8 |
| 2010s | 92.8 |
| 2020s (so far, 6 years) | 85.0 |
Ice days (max at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 47.5 |
| 1970s | 40.5 |
| 1980s | 43.7 |
| 1990s | 37.2 |
| 2000s | 34.8 |
| 2010s | 34.8 |
| 2020s (so far, 6 years) | 27.4 |
Each measure counts days in complete years only. A station is in a measure's set when it has complete years in every decade from the 1960s, so each chart compares the same places over time. A grey bar is a decade that is not over.
All climate measures for Europe
Hot Days, Warm Nights and Frost Days by Decade: North America
Up to 1,715 stations per measure, fixed sets- In North America, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 1,715 stations rose from 60.2 to 65.4 between the 1960s and the 2010s; the 2020s so far (6 years) average 67.9.
- In North America, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 1,715 stations rose from 12.8 to 15.4 between the 1960s and the 2010s; the 2020s so far (6 years) average 16.7.
- In North America, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 1,715 stations rose from 1.2 to 1.7 between the 1960s and the 2010s; the 2020s so far (6 years) average 2.2.
- In North America, the mean number of warm nights, with a daily minimum at or above 20 C (68 F) per year at 1,658 stations rose from 24.2 to 33.8 between the 1960s and the 2010s; the 2020s so far (6 years) average 33.9.
- In North America, the mean number of frost days, with a daily minimum at or below 0 C (32 F) per year at 1,658 stations fell from 125.4 to 116.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 113.7.
- In North America, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 1,715 stations fell from 32.4 to 31.4 between the 1960s and the 2010s; the 2020s so far (6 years) average 26.3.
Days at or above 30 C
| Decade | Mean days per year |
|---|---|
| 1960s | 60.2 |
| 1970s | 60.5 |
| 1980s | 62.4 |
| 1990s | 58.5 |
| 2000s | 61.3 |
| 2010s | 65.4 |
| 2020s (so far, 6 years) | 67.9 |
Days at or above 35 C
| Decade | Mean days per year |
|---|---|
| 1960s | 12.8 |
| 1970s | 12.5 |
| 1980s | 15.2 |
| 1990s | 13.0 |
| 2000s | 14.3 |
| 2010s | 15.4 |
| 2020s (so far, 6 years) | 16.7 |
Days at or above 40 C
| Decade | Mean days per year |
|---|---|
| 1960s | 1.2 |
| 1970s | 1.2 |
| 1980s | 1.5 |
| 1990s | 1.3 |
| 2000s | 1.6 |
| 2010s | 1.7 |
| 2020s (so far, 6 years) | 2.2 |
Tropical nights (min at or above 20 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 24.2 |
| 1970s | 25.4 |
| 1980s | 27.9 |
| 1990s | 28.1 |
| 2000s | 29.5 |
| 2010s | 33.8 |
| 2020s (so far, 6 years) | 33.9 |
Frost days (min at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 125.4 |
| 1970s | 124.0 |
| 1980s | 120.9 |
| 1990s | 116.9 |
| 2000s | 117.6 |
| 2010s | 116.5 |
| 2020s (so far, 6 years) | 113.7 |
Ice days (max at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 32.4 |
| 1970s | 33.8 |
| 1980s | 31.3 |
| 1990s | 28.6 |
| 2000s | 29.9 |
| 2010s | 31.4 |
| 2020s (so far, 6 years) | 26.3 |
Each measure counts days in complete years only. A station is in a measure's set when it has complete years in every decade from the 1960s, so each chart compares the same places over time. A grey bar is a decade that is not over.
All climate measures for North America
Hot Days, Warm Nights and Frost Days by Decade: Oceania
Up to 68 stations per measure, fixed sets- In Oceania, the mean number of days with a daily maximum at or above 30 C (86 F) per year at 68 stations rose from 99.7 to 116.8 between the 1960s and the 2010s; the 2020s so far (6 years) average 115.4.
- In Oceania, the mean number of days with a daily maximum at or above 35 C (95 F) per year at 68 stations rose from 28.1 to 34.7 between the 1960s and the 2010s; the 2020s so far (6 years) average 34.5.
- In Oceania, the mean number of days with a daily maximum at or above 40 C (104 F) per year at 68 stations rose from 4.5 to 7.1 between the 1960s and the 2010s; the 2020s so far (6 years) average 6.6.
- In Oceania, the mean number of warm nights, with a daily minimum at or above 20 C (68 F) per year at 67 stations rose from 81.2 to 92.5 between the 1960s and the 2010s; the 2020s so far (6 years) average 93.3.
- In Oceania, the mean number of frost days, with a daily minimum at or below 0 C (32 F) per year at 67 stations fell from 4.6 to 4.2 between the 1960s and the 2010s; the 2020s so far (6 years) average 3.4.
- In Oceania, the mean number of ice days, with a daily maximum at or below 0 C (32 F) per year at 68 stations was 0.0 in both between the 1960s and the 2010s; the 2020s so far (6 years) average 0.0.
Days at or above 30 C
| Decade | Mean days per year |
|---|---|
| 1960s | 99.7 |
| 1970s | 100.5 |
| 1980s | 107.8 |
| 1990s | 106.5 |
| 2000s | 112.3 |
| 2010s | 116.8 |
| 2020s (so far, 6 years) | 115.4 |
Days at or above 35 C
| Decade | Mean days per year |
|---|---|
| 1960s | 28.1 |
| 1970s | 26.5 |
| 1980s | 30.1 |
| 1990s | 29.4 |
| 2000s | 32.1 |
| 2010s | 34.7 |
| 2020s (so far, 6 years) | 34.5 |
Days at or above 40 C
| Decade | Mean days per year |
|---|---|
| 1960s | 4.5 |
| 1970s | 4.5 |
| 1980s | 5.5 |
| 1990s | 5.2 |
| 2000s | 6.0 |
| 2010s | 7.1 |
| 2020s (so far, 6 years) | 6.6 |
Tropical nights (min at or above 20 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 81.2 |
| 1970s | 83.9 |
| 1980s | 86.1 |
| 1990s | 86.5 |
| 2000s | 87.9 |
| 2010s | 92.5 |
| 2020s (so far, 6 years) | 93.3 |
Frost days (min at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 4.6 |
| 1970s | 4.2 |
| 1980s | 4.1 |
| 1990s | 4.1 |
| 2000s | 4.7 |
| 2010s | 4.2 |
| 2020s (so far, 6 years) | 3.4 |
Ice days (max at or below 0 C)
| Decade | Mean days per year |
|---|---|
| 1960s | 0.0 |
| 1970s | 0.0 |
| 1980s | 0.0 |
| 1990s | 0.0 |
| 2000s | 0.0 |
| 2010s | 0.0 |
| 2020s (so far, 6 years) | 0.0 |
Each measure counts days in complete years only. A station is in a measure's set when it has complete years in every decade from the 1960s, so each chart compares the same places over time. A grey bar is a decade that is not over.
All climate measures for Oceania
Countries
17 with data| Country | Stations | Days per year, first decade | Days per year, last complete decade | Change in days per year |
|---|---|---|---|---|
| Croatia | 12 | 14.9 (1960s) | 38.9 (2010s) | +24.0 |
| Romania | 20 | 22.0 (1960s) | 42.9 (2010s) | +20.9 |
| Australia | 63 | 87.4 (1960s) | 102.1 (2010s) | +14.7 |
| Kazakhstan | 13 | 56.9 (1960s) | 70.9 (2010s) | +14.0 |
| Spain | 44 | 42.7 (1960s) | 56.6 (2010s) | +13.9 |
| France | 34 | 8.6 (1960s) | 20.5 (2010s) | +11.9 |
| Japan | 29 | 46.9 (1960s) | 56.8 (2010s) | +9.8 |
| Germany | 181 | 4.0 (1960s) | 11.2 (2010s) | +7.2 |
| China | 39 | 48.8 (1960s) | 55.1 (2010s) | +6.3 |
| United States | 1,709 | 60.0 (1960s) | 65.2 (2010s) | +5.2 |
| Russia | 38 | 5.3 (1960s) | 9.8 (2010s) | +4.4 |
| Netherlands | 12 | 1.7 (1960s) | 5.5 (2010s) | +3.8 |
| Estonia | 15 | 0.4 (1960s) | 3.2 (2010s) | +2.8 |
| Finland | 48 | 0.1 (1960s) | 1.6 (2010s) | +1.5 |
| Sweden | 62 | 0.3 (1960s) | 1.3 (2010s) | +1.0 |
| United Kingdom | 49 | 0.1 (1960s) | 0.6 (2010s) | +0.6 |
| Norway | 42 | 0.1 (1960s) | 0.4 (2010s) | +0.3 |
Ordered by the change in mean days per year between the first decade (1960s) and the last complete decade (2010s) for: Days at or above 30 C. Each country's own fixed station set is used; the station count is in the second column.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17. The figures are computed by this site from daily station records. They describe the stations in each set, not every place.