San Juan City Weather Records (RQW00011631)

Record envelope, standing records and threshold days for San Juan City (RQW00011631), PR, Puerto Rico [United States], with 62 years of record.

Key Facts for San Juan City

San Juan City (RQW00011631) is a weather station in PR, Puerto Rico [United States] at 18.47 latitude and -66.10 longitude, 6 m (20 ft) above sea level.
The station reports from 1916 to 1977, 62 years of record.
1,464 records set at San Juan City still stand.
Records are tracked for prcp: an element needs 30 years of data to be eligible.
San Juan City set a daily record precipitation of 72.1 mm (2.8 in) on 18 May 1977.

About the Station

Location: PR, Puerto Rico [United States], 18.47 latitude, -66.10 longitude.
Elevation: 6 m (20 ft).
Period of record: 1916 to 1977, 62 years.
Eligible elements: prcp.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at San Juan City. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at San Juan City, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	32.2 C (90.0 F)	16.1 C (61.0 F)	n/a	n/a
Feb	33.3 C (91.9 F)	16.7 C (62.1 F)	n/a	n/a
Mar	35.6 C (96.1 F)	17.8 C (64.0 F)	n/a	n/a
Apr	34.4 C (93.9 F)	18.3 C (64.9 F)	n/a	n/a
May	34.4 C (93.9 F)	20.0 C (68.0 F)	n/a	n/a
Jun	34.4 C (93.9 F)	20.6 C (69.1 F)	n/a	n/a
Jul	33.9 C (93.0 F)	18.3 C (64.9 F)	n/a	n/a
Aug	34.4 C (93.9 F)	19.4 C (66.9 F)	n/a	n/a
Sep	34.4 C (93.9 F)	19.4 C (66.9 F)	n/a	n/a
Oct	35.6 C (96.1 F)	20.6 C (69.1 F)	n/a	n/a
Nov	32.8 C (91.0 F)	19.4 C (66.9 F)	n/a	n/a
Dec	32.2 C (90.0 F)	18.3 C (64.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at San Juan City still stand. 1955 holds the most, with 89.

Standing records at San Juan City by the year they were set
Year set	Standing records
1916	70
1917	36
1950	78
1951	80
1952	67
1953	41
1954	45
1955	89
1956	79
1957	44
1958	75
1959	43
1960	52
1961	49
1963	56
1964	41
1965	46
1966	41
1967	48
1968	61
1969	80
1970	45
1971	28
1972	17
1973	29
1974	46
1975	24
1976	32
1977	22

All-Time Record Progression

1 new records

1 all-time records were set at San Juan City between 23 April 1973 and 23 April 1973. Each dot is a new record.

Wettest Day of Each Month

Apr: 146.1 mm (5.8 in)

The wettest day on record for each calendar month at San Juan City. The most was 146.1 mm (5.8 in) on 23 April 1973.

Record daily precipitation for each month at San Juan City
Month	Record daily precipitation (mm)	Date
Jan	112.0 mm (4.4 in)	24 January 1977
Feb	112.0 mm (4.4 in)	24 February 1918
Mar	127.0 mm (5.0 in)	25 March 1956
Apr	146.1 mm (5.8 in)	23 April 1973
May	101.6 mm (4.0 in)	17 May 1965
Jun	133.6 mm (5.3 in)	12 June 1919
Jul	81.0 mm (3.2 in)	18 July 1950
Aug	102.9 mm (4.1 in)	6 August 1955
Sep	68.3 mm (2.7 in)	16 September 1954
Oct	136.4 mm (5.4 in)	7 October 1970
Nov	97.3 mm (3.8 in)	8 November 1952
Dec	113.3 mm (4.5 in)	10 December 1970

Period of Record Coverage

1916 to 1977

29 years of record at San Juan City, 1916 to 1977. 9 years have data for under 90 percent of days and are left out of rankings: 1916, 1917, 1950, 1970, 1973, 1974, 1975, 1976 and others.

Days with data per year at San Juan City
Year	Days with data	Share of year	Complete
1916	214	58%	No
1917	59	16%	No
1950	306	84%	No
1951	365	100%	Yes
1952	366	100%	Yes
1953	365	100%	Yes
1954	352	96%	Yes
1955	365	100%	Yes
1956	365	100%	Yes
1957	365	100%	Yes
1958	365	100%	Yes
1959	365	100%	Yes
1960	362	99%	Yes
1961	365	100%	Yes
1963	365	100%	Yes
1964	366	100%	Yes
1965	365	100%	Yes
1966	364	100%	Yes
1967	364	100%	Yes
1968	362	99%	Yes
1969	360	99%	Yes
1970	318	87%	No
1971	363	99%	Yes
1972	356	97%	Yes
1973	257	70%	No
1974	249	68%	No
1975	229	63%	No
1976	254	69%	No
1977	109	30%	No

Latest Records

Latest records at San Juan City
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 May 1977	San Juan City, PR	daily rain	72.1 mm (2.8 in)	11.6 mm (0.5 in)	12 years	17 of 100 (Routine)
22 February 1977	San Juan City, PR	daily rain (Tie)	11.4 mm (0.4 in)	tie	5 years	1 of 100 (Routine)
24 January 1977	San Juan City, PR	monthly rain	112.0 mm (4.4 in)	26.9 mm (1.1 in)	7 years	54 of 100 (Notable)
21 January 1977	San Juan City, PR	daily rain	69.3 mm (2.7 in)	51.3 mm (2.0 in)	18 years	51 of 100 (Notable)
28 December 1976	San Juan City, PR	daily rain	30.2 mm (1.2 in)	5.8 mm (0.23 in)	22 years	16 of 100 (Routine)
1 November 1976	San Juan City, PR	daily rain	93.0 mm (3.7 in)	39.4 mm (1.6 in)	17 years	38 of 100 (Notable)
15 September 1976	San Juan City, PR	daily rain	41.7 mm (1.6 in)	9.2 mm (0.36 in)	25 years	21 of 100 (Routine)
9 September 1976	San Juan City, PR	daily rain	26.4 mm (1.0 in)	5.3 mm (0.21 in)	7 years	12 of 100 (Routine)
3 May 1976	San Juan City, PR	daily rain	65.5 mm (2.6 in)	35.8 mm (1.4 in)	52 years	47 of 100 (Notable)
16 April 1976	San Juan City, PR	daily rain	79.2 mm (3.1 in)	68.8 mm (2.7 in)	10 years	49 of 100 (Notable)
22 March 1976	San Juan City, PR	daily rain	23.1 mm (0.9 in)	15.0 mm (0.6 in)	5 years	20 of 100 (Routine)
4 March 1976	San Juan City, PR	daily rain	13.2 mm (0.5 in)	5.1 mm (0.20 in)	59 years	20 of 100 (Routine)
8 December 1975	San Juan City, PR	daily rain	25.7 mm (1.0 in)	8.9 mm (0.35 in)	58 years	30 of 100 (Routine)
24 November 1975	San Juan City, PR	daily rain	42.9 mm (1.7 in)	16.7 mm (0.7 in)	8 years	19 of 100 (Routine)
18 November 1975	San Juan City, PR	daily rain	27.4 mm (1.1 in)	13.4 mm (0.5 in)	57 years	32 of 100 (Routine)
17 September 1975	San Juan City, PR	daily rain	54.6 mm (2.1 in)	20.8 mm (0.8 in)	58 years	42 of 100 (Notable)
2 September 1975	San Juan City, PR	daily rain	26.9 mm (1.1 in)	3.0 mm (0.12 in)	12 years	11 of 100 (Routine)
11 August 1975	San Juan City, PR	daily rain	73.2 mm (2.9 in)	40.4 mm (1.6 in)	16 years	44 of 100 (Notable)
7 January 1975	San Juan City, PR	daily rain	6.1 mm (0.24 in)	1.8 mm (0.07 in)	51 years	20 of 100 (Routine)
2 January 1975	San Juan City, PR	daily rain	20.8 mm (0.8 in)	10.6 mm (0.4 in)	16 years	20 of 100 (Routine)

Climate Trend

20 complete years, 1951 to 1972

One stripe for each of 20 complete years at San Juan City, 1951 to 1972. Blue stripes are years cooler than the station's own mean of 25.9 C (78.7 F); red stripes are warmer. The coolest year was 1967, at 25.5 C (77.8 F), and the warmest was 1969, at 26.5 C (79.7 F). The strongest colour marks a difference of 0.6 C (1.1 F).

Annual mean temperature at San Juan City as warming stripes, 1951 to 1972
Year	Annual mean temperature	Difference from the station mean
1951	25.8 C	-0.10 C
1952	25.9 C	-0.01 C
1953	26.0 C	+0.08 C
1954	25.8 C	-0.09 C
1955	25.8 C	-0.10 C
1956	25.5 C	-0.42 C
1957	25.8 C	-0.09 C
1958	26.3 C	+0.34 C
1959	26.1 C	+0.13 C
1960	26.2 C	+0.31 C
1961	25.8 C	-0.11 C
1963	26.2 C	+0.26 C
1964	26.0 C	+0.11 C
1965	25.6 C	-0.31 C
1966	26.0 C	+0.10 C
1967	25.5 C	-0.45 C
1968	25.5 C	-0.43 C
1969	26.5 C	+0.57 C
1971	26.0 C	+0.04 C
1972	26.1 C	+0.18 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1916 to 1977

Yearly extremes at San Juan City: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	35.6 C (96.1 F)	1958	33.9 C (93.0 F)	29
Coldest night (TNn)	16.1 C (61.0 F)	1975	18.3 C (64.9 F)	29
Wettest day (Rx1day)	146.1 mm (5.8 in)	1973	90.0 mm (3.5 in)	36
Wettest five days (Rx5day)	273.1 mm (10.8 in)	1970	135.5 mm (5.3 in)	36
Longest dry spell (CDD)	33 days	1973	14 days	36

Hottest day (TXx)

The hottest day of the year at San Juan City, 1916 to 1977. The record is 35.6 C (96.1 F) in 1958, marked on the chart; the median year is 33.9 C (93.0 F).

Hottest day (TXx) at San Juan City by year
Year	Hottest day (TXx)
1916	32.8 C (91.0 F)
1917	27.8 C (82.0 F)
1918	n/a
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1950	33.3 C (91.9 F)
1951	33.9 C (93.0 F)
1952	33.9 C (93.0 F)
1953	33.3 C (91.9 F)
1954	33.3 C (91.9 F)
1955	34.4 C (93.9 F)
1956	33.3 C (91.9 F)
1957	33.9 C (93.0 F)
1958	35.6 C (96.1 F)
1959	32.8 C (91.0 F)
1960	33.9 C (93.0 F)
1961	34.4 C (93.9 F)
1963	35.6 C (96.1 F)
1964	34.4 C (93.9 F)
1965	33.9 C (93.0 F)
1966	33.9 C (93.0 F)
1967	33.9 C (93.0 F)
1968	33.3 C (91.9 F)
1969	33.9 C (93.0 F)
1970	32.8 C (91.0 F)
1971	33.9 C (93.0 F)
1972	33.9 C (93.0 F)
1973	34.4 C (93.9 F)
1974	33.9 C (93.0 F)
1975	34.4 C (93.9 F)
1976	34.4 C (93.9 F)
1977	34.4 C (93.9 F)

Coldest night (TNn)

The coldest night of the year at San Juan City, 1916 to 1977. The record is 16.1 C (61.0 F) in 1975, marked on the chart; the median year is 18.3 C (64.9 F).

Coldest night (TNn) at San Juan City by year
Year	Coldest night (TNn)
1916	18.3 C (64.9 F)
1917	16.7 C (62.1 F)
1918	n/a
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1950	17.8 C (64.0 F)
1951	17.8 C (64.0 F)
1952	18.3 C (64.9 F)
1953	18.9 C (66.0 F)
1954	17.2 C (63.0 F)
1955	18.3 C (64.9 F)
1956	18.9 C (66.0 F)
1957	18.9 C (66.0 F)
1958	18.9 C (66.0 F)
1959	20.0 C (68.0 F)
1960	20.0 C (68.0 F)
1961	20.0 C (68.0 F)
1963	18.3 C (64.9 F)
1964	18.9 C (66.0 F)
1965	17.8 C (64.0 F)
1966	20.0 C (68.0 F)
1967	18.3 C (64.9 F)
1968	17.8 C (64.0 F)
1969	17.8 C (64.0 F)
1970	19.4 C (66.9 F)
1971	17.2 C (63.0 F)
1972	19.4 C (66.9 F)
1973	18.3 C (64.9 F)
1974	18.3 C (64.9 F)
1975	16.1 C (61.0 F)
1976	17.8 C (64.0 F)
1977	17.8 C (64.0 F)

Wettest day (Rx1day)

The wettest day of the year at San Juan City, 1916 to 1977. The record is 146.1 mm (5.8 in) in 1973, marked on the chart; the median year is 90.0 mm (3.5 in).

Wettest day (Rx1day) at San Juan City by year
Year	Wettest day (Rx1day)
1916	50.5 mm (2.0 in)
1917	77.0 mm (3.0 in)
1918	112.0 mm (4.4 in)
1919	133.6 mm (5.3 in)
1920	65.5 mm (2.6 in)
1921	45.0 mm (1.8 in)
1922	96.8 mm (3.8 in)
1923	69.1 mm (2.7 in)
1924	64.8 mm (2.6 in)
1950	93.5 mm (3.7 in)
1951	88.6 mm (3.5 in)
1952	97.3 mm (3.8 in)
1953	67.8 mm (2.7 in)
1954	68.3 mm (2.7 in)
1955	102.9 mm (4.1 in)
1956	127.0 mm (5.0 in)
1957	51.1 mm (2.0 in)
1958	79.8 mm (3.1 in)
1959	101.9 mm (4.0 in)
1960	78.5 mm (3.1 in)
1961	82.3 mm (3.2 in)
1963	65.5 mm (2.6 in)
1964	93.5 mm (3.7 in)
1965	101.6 mm (4.0 in)
1966	64.3 mm (2.5 in)
1967	101.6 mm (4.0 in)
1968	116.1 mm (4.6 in)
1969	85.1 mm (3.4 in)
1970	136.4 mm (5.4 in)
1971	81.0 mm (3.2 in)
1972	68.1 mm (2.7 in)
1973	146.1 mm (5.8 in)
1974	95.5 mm (3.8 in)
1975	91.4 mm (3.6 in)
1976	93.0 mm (3.7 in)
1977	112.0 mm (4.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at San Juan City, 1916 to 1977. The record is 273.1 mm (10.8 in) in 1970, marked on the chart; the median year is 135.5 mm (5.3 in).

Wettest five days (Rx5day) at San Juan City by year
Year	Wettest five days (Rx5day)
1916	127.7 mm (5.0 in)
1917	184.0 mm (7.2 in)
1918	134.9 mm (5.3 in)
1919	168.9 mm (6.6 in)
1920	113.3 mm (4.5 in)
1921	90.4 mm (3.6 in)
1922	157.4 mm (6.2 in)
1923	123.5 mm (4.9 in)
1924	137.2 mm (5.4 in)
1950	206.6 mm (8.1 in)
1951	195.8 mm (7.7 in)
1952	126.2 mm (5.0 in)
1953	117.1 mm (4.6 in)
1954	99.9 mm (3.9 in)
1955	110.3 mm (4.3 in)
1956	177.6 mm (7.0 in)
1957	96.7 mm (3.8 in)
1958	160.8 mm (6.3 in)
1959	148.1 mm (5.8 in)
1960	131.9 mm (5.2 in)
1961	171.0 mm (6.7 in)
1963	136.1 mm (5.4 in)
1964	132.9 mm (5.2 in)
1965	250.0 mm (9.8 in)
1966	106.0 mm (4.2 in)
1967	107.0 mm (4.2 in)
1968	164.4 mm (6.5 in)
1969	132.8 mm (5.2 in)
1970	273.1 mm (10.8 in)
1971	119.1 mm (4.7 in)
1972	107.0 mm (4.2 in)
1973	254.3 mm (10.0 in)
1974	178.0 mm (7.0 in)
1975	155.9 mm (6.1 in)
1976	112.0 mm (4.4 in)
1977	197.5 mm (7.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at San Juan City, 1916 to 1977. The record is 33 days in 1973, marked on the chart; the median year is 14 days.

Longest dry spell (CDD) at San Juan City by year
Year	Longest dry spell (CDD)
1916	29 days
1917	8 days
1918	11 days
1919	16 days
1920	25 days
1921	10 days
1922	10 days
1923	15 days
1924	19 days
1950	12 days
1951	23 days
1952	16 days
1953	12 days
1954	14 days
1955	21 days
1956	13 days
1957	28 days
1958	16 days
1959	10 days
1960	11 days
1961	13 days
1963	16 days
1964	16 days
1965	13 days
1966	21 days
1967	13 days
1968	11 days
1969	20 days
1970	11 days
1971	13 days
1972	16 days
1973	33 days
1974	17 days
1975	13 days
1976	12 days
1977	14 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Download the Data

Data for San Juan City standing records by year: CSV or JSON. Field meanings are on the data page.
Data for San Juan City threshold days by year: CSV or JSON. Field meanings are on the data page.

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 (17 October 2026). Records are computed by this site and are not official.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).