Extreme rain in United States, 11 July to 9 August 2021

Name: Extreme rain in United States, 11 July to 9 August 2021
Start: 2021-07-11
End: 2021-08-09
Location: United States

Extreme rain in United States, 11 July to 9 August 2021: 1,001 records at 713 stations, peak on 1 August 2021. Closed.

Data as of 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Key Facts

Extreme rain in United States, 11 July to 9 August 2021 set or tied 1,001 station records at 713 stations.
It ran from 11 July 2021 to 9 August 2021 (30 days) and its peak day was 1 August 2021.
Status: closed.
Black Rock set a monthly record daily precipitation of 54.4 mm (2.1 in) on 1 August 2021.
The busiest day was 1 August 2021 with 113 records.
The oldest broken record in the ranked list had stood for 127 years.

Footprint

11 July to 9 August 2021

The area covered by Extreme rain in United States, 11 July to 9 August 2021 is outlined, with 19 of the stations that set records marked, coloured by record type. Made with Natural Earth.

Footprint of Extreme rain in United States, 11 July to 9 August 2021: stations that set records in the event
Station	Type	Value	Date
Black Rock	Record daily precipitation	54.4 mm (2.1 in)	2021-08-01
Cuyamaca	Record daily precipitation	56.4 mm (2.2 in)	2021-07-26
Tooele	Record daily precipitation	27.9 mm (1.1 in)	2021-08-02
Saint Johns	Record daily precipitation	49.5 mm (1.9 in)	2021-07-23
Mtn Home AFB	Record daily precipitation	32.0 mm (1.3 in)	2021-07-31
Williams	Record daily precipitation	66.0 mm (2.6 in)	2021-07-21
Idaho Falls 16 SE	Record daily precipitation	46.5 mm (1.8 in)	2021-07-30
Gold Center	Record daily precipitation	35.6 mm (1.4 in)	2021-07-31
Walnut Canyon Nm	Record daily precipitation	94.2 mm (3.7 in)	2021-07-14
Alpine	Record daily precipitation	40.6 mm (1.6 in)	2021-07-25
Trinidad	Record daily precipitation	78.7 mm (3.1 in)	2021-07-31
Hope	Record daily precipitation	41.9 mm (1.6 in)	2021-08-01
Idaho Falls FAA AP	Record daily precipitation	32.5 mm (1.3 in)	2021-07-31
Ely AP	Record daily precipitation	25.9 mm (1.0 in)	2021-07-22
Boise Lucky Peak Dam	Record daily precipitation	42.2 mm (1.7 in)	2021-07-31
Strawberry Divide	Record daily precipitation	55.9 mm (2.2 in)	2021-07-31
Trinity Mtn.	Record daily precipitation	71.1 mm (2.8 in)	2021-08-01
Pahrump 4 NW	Record daily precipitation	31.5 mm (1.2 in)	2021-07-27
Rocky Basin-Settleme	Record daily precipitation	78.7 mm (3.1 in)	2021-08-01

Records per Day

Peak day 113

Records set or tied each day from 11 July 2021 to 9 August 2021. The most in one day was 113 on 1 August 2021.

Records per day during Extreme rain in United States, 11 July to 9 August 2021
Date	Records
2021-07-11	1
2021-07-12	4
2021-07-13	20
2021-07-14	32
2021-07-15	11
2021-07-16	12
2021-07-17	5
2021-07-18	11
2021-07-19	16
2021-07-20	35
2021-07-21	26
2021-07-22	25
2021-07-23	53
2021-07-24	31
2021-07-25	24
2021-07-26	52
2021-07-27	32
2021-07-28	39
2021-07-29	45
2021-07-30	94
2021-07-31	87
2021-08-01	113
2021-08-02	80
2021-08-03	44
2021-08-04	16
2021-08-05	7
2021-08-06	20
2021-08-07	6
2021-08-08	42
2021-08-09	18

Top Records by Margin

Margin over the record replaced

Top records of Extreme rain in United States, 11 July to 9 August 2021 ranked by margin
Cuyamaca, 07-26	42.9 mm (1.7 in)
Trinity Mtn., 08-01	35.5 mm (1.4 in)
Rocky Basin-Settleme, 08-01	35.5 mm (1.4 in)
Hope, 08-01	34.0 mm (1.3 in)
Walnut Canyon Nm, 07-14	33.0 mm (1.3 in)
Saint Johns, 07-23	29.2 mm (1.1 in)
Williams, 07-21	28.2 mm (1.1 in)
Mtn Home AFB, 08-01	26.9 mm (1.1 in)
Idaho Falls FAA AP, 07-31	23.6 mm (0.9 in)
Strawberry Divide, 07-31	22.9 mm (0.9 in)
Pahrump 4 NW, 07-27	21.6 mm (0.9 in)
Tooele, 08-02	21.5 mm (0.8 in)
Mtn Home AFB, 07-31	20.1 mm (0.8 in)
Idaho Falls 16 SE, 07-30	20.1 mm (0.8 in)
Alpine, 07-25	19.5 mm (0.8 in)

Margin is how far the new value is beyond the record it replaced. Ties are not shown.

Margin Against Age of the Broken Record

500 records plotted by how far they beat the old record (across) and how many years the old record had stood (up). Long standing records beaten by a wide margin sit in the top right.

Margin against age of the broken record in Extreme rain in United States, 11 July to 9 August 2021
Margin (mm)	Years the old record stood
17	117
43	119
22	115
29	88
20	51
28	103
20	37
15	39
27	60
20	91
33	14
12	99
34	86
24	55
14	60
23	29
36	27
19	42
22	71
36	22
28	29
18	50
21	47
29	36
14	59
11	49
15	98
40	43
18	29
19	39
33	40
20	34
20	44
27	43
4	127
20	10
9	98
20	38
18	34
33	36
43	7
15	27
3	115
17	56
20	36
20	35
25	36
33	36
18	36
46	34
14	37
12	56
19	31
23	30
30	8
31	23
19	36
7	90
24	63
8	102
25	36
24	36
25	47
20	32
26	32
7	88
16	66
4	85
7	103
18	34
23	35
38	28
30	46
7	106
5	80
13	8
13	36
12	55
20	27
23	36
24	22
15	28
27	15
25	15
9	70
9	126
13	32
15	15
18	16
31	15
25	14
28	38
18	27
12	80
13	68
11	54
14	20
16	10
5	102
20	27
25	8
43	8
28	32
36	8
10	60
24	2
7	78
20	48
5	104
7	108
4	98
13	30
18	32
25	7
20	34
15	6
8	65
36	28
4	112
5	127
4	59
11	44
5	95
13	52
21	8
13	30
10	37
15	38
7	56
2	116
7	64
7	70
2	110
12	40
14	28
18	32
20	23
30	2
16	43
12	68
11	64
5	56
10	44
1	99
9	70
8	3
2	127
26	10
18	22
2	103
15	24
23	7
18	36
9	76
6	90
2	104
1	127
1	107
6	78
1	116
13	28
20	22
10	39
15	27
4	76
14	48
0	112
0	119
0	116
1	119
14	10
1	108
3	94
1	118
9	55
7	90
13	30
1	99
18	31
18	28
15	38
13	27
12	44
5	66
6	60
6	18
5	80
2	90
10	46
10	38
15	30
8	26
13	31
18	27
25	22
37	12
7	10
23	8
21	44
10	52

Compared With Other Events

Station records per event

Station records in Extreme rain in United States, 11 July to 9 August 2021 compared with similar events
Extreme rain in United States and Mexico, 23 February to 15 March 2019	2,223 records
Extreme rain in United States, 3 to 19 January 2024	2,133 records
Extreme rain in Australia, 7 to 26 March 2021	2,099 records
Extreme rain in United States and Mexico, 29 September to 19 October 2018	1,970 records
Extreme rain in United States, 19 December 2022 to 13 January 2023	1,941 records
Extreme rain in United States, 11 July to 9 August 2021 (this event)	1,001 records

Every Record Set

20 of 1,001

Every record set or tied during Extreme rain in United States, 11 July to 9 August 2021, in date order
Date	Station	Record	Value	Margin	Years stood	Significance
2021-07-14	Walnut Canyon Nm	Record daily precipitation	94.2 mm (3.7 in)	33.0 mm (1.3 in)	14	64 of 100 (Major)
2021-07-21	Williams	Record daily precipitation	66.0 mm (2.6 in)	28.2 mm (1.1 in)	103	71 of 100 (Major)
2021-07-22	Ely AP	Record daily precipitation	25.9 mm (1.0 in)	19.3 mm (0.8 in)	42	62 of 100 (Major)
2021-07-23	Saint Johns	Record daily precipitation	49.5 mm (1.9 in)	29.2 mm (1.1 in)	88	76 of 100 (Major)
2021-07-25	Alpine	Record daily precipitation	40.6 mm (1.6 in)	19.5 mm (0.8 in)	91	64 of 100 (Major)
2021-07-26	Cuyamaca	Record daily precipitation	56.4 mm (2.2 in)	42.9 mm (1.7 in)	119	80 of 100 (Exceptional)
2021-07-27	Pahrump 4 NW	Record daily precipitation	31.5 mm (1.2 in)	21.6 mm (0.9 in)	71	61 of 100 (Major)
2021-07-30	Idaho Falls 16 SE	Record daily precipitation	46.5 mm (1.8 in)	20.1 mm (0.8 in)	37	67 of 100 (Major)
2021-07-31	Mtn Home AFB	Record daily precipitation	32.0 mm (1.3 in)	20.1 mm (0.8 in)	51	72 of 100 (Major)
2021-07-31	Gold Center	Record daily precipitation	35.6 mm (1.4 in)	15.3 mm (0.6 in)	39	65 of 100 (Major)
2021-07-31	Trinidad	Record daily precipitation	78.7 mm (3.1 in)	12.4 mm (0.5 in)	99	64 of 100 (Major)
2021-07-31	Idaho Falls FAA AP	Record daily precipitation	32.5 mm (1.3 in)	23.6 mm (0.9 in)	55	63 of 100 (Major)
2021-07-31	Boise Lucky Peak Dam	Record daily precipitation	42.2 mm (1.7 in)	14.0 mm (0.6 in)	60	62 of 100 (Major)
2021-07-31	Strawberry Divide	Record daily precipitation	55.9 mm (2.2 in)	22.9 mm (0.9 in)	29	62 of 100 (Major)
2021-08-01	Black Rock	Record daily precipitation	54.4 mm (2.1 in)	16.6 mm (0.7 in)	117	81 of 100 (Exceptional)
2021-08-01	Mtn Home AFB	Record daily precipitation	29.7 mm (1.2 in)	26.9 mm (1.1 in)	60	65 of 100 (Major)
2021-08-01	Hope	Record daily precipitation	41.9 mm (1.6 in)	34.0 mm (1.3 in)	86	64 of 100 (Major)
2021-08-01	Trinity Mtn.	Record daily precipitation	71.1 mm (2.8 in)	35.5 mm (1.4 in)	27	62 of 100 (Major)
2021-08-01	Rocky Basin-Settleme	Record daily precipitation	78.7 mm (3.1 in)	35.5 mm (1.4 in)	22	60 of 100 (Major)
2021-08-02	Tooele	Record daily precipitation	27.9 mm (1.1 in)	21.5 mm (0.8 in)	115	80 of 100 (Exceptional)

The daily ledgers keep a limited number of records per day, so this list has 20 of the 1,001 records the event counts. The counts above use the full total.

Related Headlines

Third party news, headline and link only

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. Events are found by this site from station records and are not official designations. Records are provisional until reprocessed.

Margin (mm)	Years the old record stood
17	117
43	119
22	115
29	88
20	51
28	103
20	37
15	39
27	60
20	91
33	14
12	99
34	86
24	55
14	60
23	29
36	27
19	42
22	71
36	22
28	29
18	50
21	47
29	36
14	59
11	49
15	98
40	43
18	29
19	39
33	40
20	34
20	44
27	43
4	127
20	10
9	98
20	38
18	34
33	36
43	7
15	27
3	115
17	56
20	36
20	35
25	36
33	36
18	36
46	34
14	37
12	56
19	31
23	30
30	8
31	23
19	36
7	90
24	63
8	102
25	36
24	36
25	47
20	32
26	32
7	88
16	66
4	85
7	103
18	34
23	35
38	28
30	46
7	106
5	80
13	8
13	36
12	55
20	27
23	36
24	22
15	28
27	15
25	15
9	70
9	126
13	32
15	15
18	16
31	15
25	14
28	38
18	27
12	80
13	68
11	54
14	20
16	10
5	102
20	27
25	8
43	8
28	32
36	8
10	60
24	2
7	78
20	48
5	104
7	108
4	98
13	30
18	32
25	7
20	34
15	6
8	65
36	28
4	112
5	127
4	59
11	44
5	95
13	52
21	8
13	30
10	37
15	38
7	56
2	116
7	64
7	70
2	110
12	40
14	28
18	32
20	23
30	2
16	43
12	68
11	64
5	56
10	44
1	99
9	70
8	3
2	127
26	10
18	22
2	103
15	24
23	7
18	36
9	76
6	90
2	104
1	127
1	107
6	78
1	116
13	28
20	22
10	39
15	27
4	76
14	48
0	112
0	119
0	116
1	119
14	10
1	108
3	94
1	118
9	55
7	90
13	30
1	99
18	31
18	28
15	38
13	27
12	44
5	66
6	60
6	18
5	80
2	90
10	46
10	38
15	30
8	26
13	31
18	27
25	22
37	12
7	10
23	8
21	44
10	52

Margin (mm)	Years the old record stood
17	117
43	119
22	115
29	88
20	51
28	103
20	37
15	39
27	60
20	91
33	14
12	99
34	86
24	55
14	60
23	29
36	27
19	42
22	71
36	22
28	29
18	50
21	47
29	36
14	59
11	49
15	98
40	43
18	29
19	39
33	40
20	34
20	44
27	43
4	127
20	10
9	98
20	38
18	34
33	36
43	7
15	27
3	115
17	56
20	36
20	35
25	36
33	36
18	36
46	34
14	37
12	56
19	31
23	30
30	8
31	23
19	36
7	90
24	63
8	102
25	36
24	36
25	47
20	32
26	32
7	88
16	66
4	85
7	103
18	34
23	35
38	28
30	46
7	106
5	80
13	8
13	36
12	55
20	27
23	36
24	22
15	28
27	15
25	15
9	70
9	126
13	32
15	15
18	16
31	15
25	14
28	38
18	27
12	80
13	68
11	54
14	20
16	10
5	102
20	27
25	8
43	8
28	32
36	8
10	60
24	2
7	78
20	48
5	104
7	108
4	98
13	30
18	32
25	7
20	34
15	6
8	65
36	28
4	112
5	127
4	59
11	44
5	95
13	52
21	8
13	30
10	37
15	38
7	56
2	116
7	64
7	70
2	110
12	40
14	28
18	32
20	23
30	2
16	43
12	68
11	64
5	56
10	44
1	99
9	70
8	3
2	127
26	10
18	22
2	103
15	24
23	7
18	36
9	76
6	90
2	104
1	127
1	107
6	78
1	116
13	28
20	22
10	39
15	27
4	76
14	48
0	112
0	119
0	116
1	119
14	10
1	108
3	94
1	118
9	55
7	90
13	30
1	99
18	31
18	28
15	38
13	27
12	44
5	66
6	60
6	18
5	80
2	90
10	46
10	38
15	30
8	26
13	31
18	27
25	22
37	12
7	10
23	8
21	44
10	52

Margin (mm)	Years the old record stood
17	117
43	119
22	115
29	88
20	51
28	103
20	37
15	39
27	60
20	91
33	14
12	99
34	86
24	55
14	60
23	29
36	27
19	42
22	71
36	22
28	29
18	50
21	47
29	36
14	59
11	49
15	98
40	43
18	29
19	39
33	40
20	34
20	44
27	43
4	127
20	10
9	98
20	38
18	34
33	36
43	7
15	27
3	115
17	56
20	36
20	35
25	36
33	36
18	36
46	34
14	37
12	56
19	31
23	30
30	8
31	23
19	36
7	90
24	63
8	102
25	36
24	36
25	47
20	32
26	32
7	88
16	66
4	85
7	103
18	34
23	35
38	28
30	46
7	106
5	80
13	8
13	36
12	55
20	27
23	36
24	22
15	28
27	15
25	15
9	70
9	126
13	32
15	15
18	16
31	15
25	14
28	38
18	27
12	80
13	68
11	54
14	20
16	10
5	102
20	27
25	8
43	8
28	32
36	8
10	60
24	2
7	78
20	48
5	104
7	108
4	98
13	30
18	32
25	7
20	34
15	6
8	65
36	28
4	112
5	127
4	59
11	44
5	95
13	52
21	8
13	30
10	37
15	38
7	56
2	116
7	64
7	70
2	110
12	40
14	28
18	32
20	23
30	2
16	43
12	68
11	64
5	56
10	44
1	99
9	70
8	3
2	127
26	10
18	22
2	103
15	24
23	7
18	36
9	76
6	90
2	104
1	127
1	107
6	78
1	116
13	28
20	22
10	39
15	27
4	76
14	48
0	112
0	119
0	116
1	119
14	10
1	108
3	94
1	118
9	55
7	90
13	30
1	99
18	31
18	28
15	38
13	27
12	44
5	66
6	60
6	18
5	80
2	90
10	46
10	38
15	30
8	26
13	31
18	27
25	22
37	12
7	10
23	8
21	44
10	52