Extreme rain in United States, 28 April to 4 May 2018

Name: Extreme rain in United States, 28 April to 4 May 2018
Start: 2018-04-28
End: 2018-05-04
Location: United States

Extreme rain in United States, 28 April to 4 May 2018: 208 records at 195 stations, peak on 2 May 2018. Closed.

Data as of 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Key Facts

Extreme rain in United States, 28 April to 4 May 2018 set or tied 208 station records at 195 stations.
It ran from 28 April 2018 to 4 May 2018 (7 days) and its peak day was 2 May 2018.
Status: closed.
Ferron set a monthly record daily precipitation of 30.5 mm (1.2 in) on 2 May 2018.
The busiest day was 2 May 2018 with 62 records.
The oldest broken record in the ranked list had stood for 122 years.

Footprint

28 April to 4 May 2018

The area covered by Extreme rain in United States, 28 April to 4 May 2018 is outlined, with 20 of the stations that set records marked, coloured by record type. Made with Natural Earth.

Footprint of Extreme rain in United States, 28 April to 4 May 2018: stations that set records in the event
Station	Type	Value	Date
Ferron	Record daily precipitation	30.5 mm (1.2 in)	2018-05-02
Grizzly Peak	Record daily precipitation	38.1 mm (1.5 in)	2018-05-03
Winter Park	Record daily precipitation	33.5 mm (1.3 in)	2018-05-03
Hecla 1E	Record daily precipitation	36.8 mm (1.4 in)	2018-05-03
Boysen Dam	Record daily precipitation	35.3 mm (1.4 in)	2018-05-01
Coal Creek Canyon	Record daily precipitation	54.9 mm (2.2 in)	2018-05-03
Pavillion	Record daily precipitation	30.0 mm (1.2 in)	2018-04-30
Sugar City	Record daily precipitation	19.1 mm (0.8 in)	2018-04-30
Utah Lake Lehi	Record daily precipitation	11.4 mm (0.4 in)	2018-04-30
Aspendell	Record daily precipitation	11.2 mm (0.4 in)	2018-05-01
Santa Barbara	Record daily precipitation	4.1 mm (0.16 in)	2018-05-01
Cody	Record daily precipitation	20.8 mm (0.8 in)	2018-05-01
Bright Angel Rs	Record daily precipitation	17.0 mm (0.7 in)	2018-05-02
Overton	Record daily precipitation	5.8 mm (0.23 in)	2018-05-02
Castle Dale	Record daily precipitation	20.6 mm (0.8 in)	2018-05-02
St George	Record daily precipitation	9.1 mm (0.36 in)	2018-05-02
Yellowstone Park Mammoth	Record daily precipitation	20.3 mm (0.8 in)	2018-05-02
Barstow-Daggett AP	Record daily precipitation	4.8 mm (0.19 in)	2018-05-02
Minatare Dam (Usbr)	Record daily precipitation	16.8 mm (0.7 in)	2018-05-03
Willow Creek Pass	Record daily precipitation	22.9 mm (0.9 in)	2018-05-03

Records per Day

Peak day 62

Records set or tied each day from 28 April 2018 to 4 May 2018. The most in one day was 62 on 2 May 2018.

Top Records by Margin

Margin over the record replaced

Top records of Extreme rain in United States, 28 April to 4 May 2018 ranked by margin
Coal Creek Canyon, 05-03	24.9 mm (1.0 in)
Grizzly Peak, 05-03	22.9 mm (0.9 in)
Hecla 1E, 05-03	21.8 mm (0.9 in)
Boysen Dam, 05-01	20.8 mm (0.8 in)
Winter Park, 05-03	17.0 mm (0.7 in)
Willow Creek Pass, 05-03	15.3 mm (0.6 in)
Castle Dale, 05-02	13.0 mm (0.5 in)
Cody, 05-01	10.6 mm (0.4 in)
Yellowstone Park Mammoth, 05-02	10.1 mm (0.4 in)
Sugar City, 04-30	7.4 mm (0.29 in)
Minatare Dam (Usbr), 05-03	5.9 mm (0.23 in)
Overton, 05-02	5.8 mm (0.23 in)
Pavillion, 04-30	5.6 mm (0.22 in)
Utah Lake Lehi, 04-30	5.6 mm (0.22 in)
Barstow-Daggett AP, 05-02	4.8 mm (0.19 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

208 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, 28 April to 4 May 2018
Margin (mm)	Years the old record stood
13	113
10	116
7	103
4	119
11	84
23	33
5	73
6	79
4	103
17	44
2	122
22	39
15	35
6	64
21	23
2	116
25	31
6	88
5	84
6	67
16	20
3	83
8	36
18	19
21	16
2	76
13	35
18	23
5	73
8	40
10	51
6	64
14	1
9	24
16	37
3	64
13	31
15	23
18	29
5	36
9	19
10	15
6	55
15	24
13	29
14	39
13	19
3	68
4	39
10	33
5	24
3	64
10	39
10	23
15	8
9	39
1	68
5	29
10	8
8	33
11	39
7	28
2	37
7	23
12	20
5	35
8	29
10	28
4	40
5	2
10	39
14	16
8	31
15	8
8	33
5	33
5	37
4	40
3	36
2	36
2	37
10	29
5	31
5	35
8	23
10	20
5	35
3	36
12	16
5	8
5	37
5	39
8	23
4	36
4	33
0	39
3	19
10	23
8	29
8	20
5	16
5	12
4	35
0	40
2	40
0	48
2	29
3	12
8	23
8	8
8	15
8	23
8	29
1	40
4	19
2	39
6	36
1	24
2	23
6	24
4	15
3	36
5	35
8	16
5	23
3	36
3	28
3	29
6	12
3	39
3	33
8	23
5	23
3	29
5	23
3	31
5	23
1	36
3	3
1	36
4	12
8	8
3	23
8	12
5	28
8	8
3	31
3	33
3	33
3	33
3	35
3	33
7	16
1	37
1	15
2	20
3	29
3	28
5	23
1	28
2	28
1	31
1	16
1	29
5	16
5	8
3	27
3	28
3	29
3	11
1	1
3	12
3	23
3	23
3	23
3	29
3	29
5	8
2	23
3	16
1	23
1	29
3	20
3	19
3	23
5	1
3	16
3	23
6	8
4	16
3	19
5	4
3	20
5	1
3	23
2	16
3	12
3	20
3	11
3	15

Compared With Other Events

Station records per event

Station records in Extreme rain in United States, 28 April to 4 May 2018 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, 28 April to 4 May 2018 (this event)	208 records

Every Record Set

20 of 208

Every record set or tied during Extreme rain in United States, 28 April to 4 May 2018, in date order
Date	Station	Record	Value	Margin	Years stood	Significance
2018-04-30	Pavillion	Record daily precipitation	30.0 mm (1.2 in)	5.6 mm (0.22 in)	67	40 of 100 (Notable)
2018-04-30	Sugar City	Record daily precipitation	19.1 mm (0.8 in)	7.4 mm (0.29 in)	103	20 of 100 (Routine)
2018-04-30	Utah Lake Lehi	Record daily precipitation	11.4 mm (0.4 in)	5.6 mm (0.22 in)	64	20 of 100 (Routine)
2018-05-01	Boysen Dam	Record daily precipitation	35.3 mm (1.4 in)	20.8 mm (0.8 in)	23	42 of 100 (Notable)
2018-05-01	Aspendell	Record daily precipitation	11.2 mm (0.4 in)	3.6 mm (0.14 in)	103	20 of 100 (Routine)
2018-05-01	Santa Barbara	Record daily precipitation	4.1 mm (0.16 in)	1.8 mm (0.07 in)	116	20 of 100 (Routine)
2018-05-01	Cody	Record daily precipitation	20.8 mm (0.8 in)	10.6 mm (0.4 in)	84	20 of 100 (Routine)
2018-05-02	Ferron	Record daily precipitation	30.5 mm (1.2 in)	4.1 mm (0.16 in)	119	59 of 100 (Notable)
2018-05-02	Bright Angel Rs	Record daily precipitation	17.0 mm (0.7 in)	4.6 mm (0.18 in)	84	20 of 100 (Routine)
2018-05-02	Overton	Record daily precipitation	5.8 mm (0.23 in)	5.8 mm (0.23 in)	79	20 of 100 (Routine)
2018-05-02	Castle Dale	Record daily precipitation	20.6 mm (0.8 in)	13.0 mm (0.5 in)	113	20 of 100 (Routine)
2018-05-02	St George	Record daily precipitation	9.1 mm (0.36 in)	2.2 mm (0.09 in)	122	20 of 100 (Routine)
2018-05-02	Yellowstone Park Mammoth	Record daily precipitation	20.3 mm (0.8 in)	10.1 mm (0.4 in)	116	20 of 100 (Routine)
2018-05-02	Barstow-Daggett AP	Record daily precipitation	4.8 mm (0.19 in)	4.8 mm (0.19 in)	73	20 of 100 (Routine)
2018-05-03	Grizzly Peak	Record daily precipitation	38.1 mm (1.5 in)	22.9 mm (0.9 in)	33	50 of 100 (Notable)
2018-05-03	Winter Park	Record daily precipitation	33.5 mm (1.3 in)	17.0 mm (0.7 in)	44	45 of 100 (Notable)
2018-05-03	Hecla 1E	Record daily precipitation	36.8 mm (1.4 in)	21.8 mm (0.9 in)	39	44 of 100 (Notable)
2018-05-03	Coal Creek Canyon	Record daily precipitation	54.9 mm (2.2 in)	24.9 mm (1.0 in)	31	41 of 100 (Notable)
2018-05-03	Minatare Dam (Usbr)	Record daily precipitation	16.8 mm (0.7 in)	5.9 mm (0.23 in)	88	20 of 100 (Routine)
2018-05-03	Willow Creek Pass	Record daily precipitation	22.9 mm (0.9 in)	15.3 mm (0.6 in)	35	20 of 100 (Routine)

The daily ledgers keep a limited number of records per day, so this list has 20 of the 208 records the event counts. The counts above use the full total.

Related Headlines

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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 2026-10-12. Events are found by this site from station records and are not official designations. Records are provisional until reprocessed.

Date	Records
2018-04-28	1
2018-04-29	6
2018-04-30	44
2018-05-01	38
2018-05-02	62
2018-05-03	49
2018-05-04	8

Margin (mm)	Years the old record stood
13	113
10	116
7	103
4	119
11	84
23	33
5	73
6	79
4	103
17	44
2	122
22	39
15	35
6	64
21	23
2	116
25	31
6	88
5	84
6	67
16	20
3	83
8	36
18	19
21	16
2	76
13	35
18	23
5	73
8	40
10	51
6	64
14	1
9	24
16	37
3	64
13	31
15	23
18	29
5	36
9	19
10	15
6	55
15	24
13	29
14	39
13	19
3	68
4	39
10	33
5	24
3	64
10	39
10	23
15	8
9	39
1	68
5	29
10	8
8	33
11	39
7	28
2	37
7	23
12	20
5	35
8	29
10	28
4	40
5	2
10	39
14	16
8	31
15	8
8	33
5	33
5	37
4	40
3	36
2	36
2	37
10	29
5	31
5	35
8	23
10	20
5	35
3	36
12	16
5	8
5	37
5	39
8	23
4	36
4	33
0	39
3	19
10	23
8	29
8	20
5	16
5	12
4	35
0	40
2	40
0	48
2	29
3	12
8	23
8	8
8	15
8	23
8	29
1	40
4	19
2	39
6	36
1	24
2	23
6	24
4	15
3	36
5	35
8	16
5	23
3	36
3	28
3	29
6	12
3	39
3	33
8	23
5	23
3	29
5	23
3	31
5	23
1	36
3	3
1	36
4	12
8	8
3	23
8	12
5	28
8	8
3	31
3	33
3	33
3	33
3	35
3	33
7	16
1	37
1	15
2	20
3	29
3	28
5	23
1	28
2	28
1	31
1	16
1	29
5	16
5	8
3	27
3	28
3	29
3	11
1	1
3	12
3	23
3	23
3	23
3	29
3	29
5	8
2	23
3	16
1	23
1	29
3	20
3	19
3	23
5	1
3	16
3	23
6	8
4	16
3	19
5	4
3	20
5	1
3	23
2	16
3	12
3	20
3	11
3	15

Margin (mm)	Years the old record stood
13	113
10	116
7	103
4	119
11	84
23	33
5	73
6	79
4	103
17	44
2	122
22	39
15	35
6	64
21	23
2	116
25	31
6	88
5	84
6	67
16	20
3	83
8	36
18	19
21	16
2	76
13	35
18	23
5	73
8	40
10	51
6	64
14	1
9	24
16	37
3	64
13	31
15	23
18	29
5	36
9	19
10	15
6	55
15	24
13	29
14	39
13	19
3	68
4	39
10	33
5	24
3	64
10	39
10	23
15	8
9	39
1	68
5	29
10	8
8	33
11	39
7	28
2	37
7	23
12	20
5	35
8	29
10	28
4	40
5	2
10	39
14	16
8	31
15	8
8	33
5	33
5	37
4	40
3	36
2	36
2	37
10	29
5	31
5	35
8	23
10	20
5	35
3	36
12	16
5	8
5	37
5	39
8	23
4	36
4	33
0	39
3	19
10	23
8	29
8	20
5	16
5	12
4	35
0	40
2	40
0	48
2	29
3	12
8	23
8	8
8	15
8	23
8	29
1	40
4	19
2	39
6	36
1	24
2	23
6	24
4	15
3	36
5	35
8	16
5	23
3	36
3	28
3	29
6	12
3	39
3	33
8	23
5	23
3	29
5	23
3	31
5	23
1	36
3	3
1	36
4	12
8	8
3	23
8	12
5	28
8	8
3	31
3	33
3	33
3	33
3	35
3	33
7	16
1	37
1	15
2	20
3	29
3	28
5	23
1	28
2	28
1	31
1	16
1	29
5	16
5	8
3	27
3	28
3	29
3	11
1	1
3	12
3	23
3	23
3	23
3	29
3	29
5	8
2	23
3	16
1	23
1	29
3	20
3	19
3	23
5	1
3	16
3	23
6	8
4	16
3	19
5	4
3	20
5	1
3	23
2	16
3	12
3	20
3	11
3	15

Margin (mm)	Years the old record stood
13	113
10	116
7	103
4	119
11	84
23	33
5	73
6	79
4	103
17	44
2	122
22	39
15	35
6	64
21	23
2	116
25	31
6	88
5	84
6	67
16	20
3	83
8	36
18	19
21	16
2	76
13	35
18	23
5	73
8	40
10	51
6	64
14	1
9	24
16	37
3	64
13	31
15	23
18	29
5	36
9	19
10	15
6	55
15	24
13	29
14	39
13	19
3	68
4	39
10	33
5	24
3	64
10	39
10	23
15	8
9	39
1	68
5	29
10	8
8	33
11	39
7	28
2	37
7	23
12	20
5	35
8	29
10	28
4	40
5	2
10	39
14	16
8	31
15	8
8	33
5	33
5	37
4	40
3	36
2	36
2	37
10	29
5	31
5	35
8	23
10	20
5	35
3	36
12	16
5	8
5	37
5	39
8	23
4	36
4	33
0	39
3	19
10	23
8	29
8	20
5	16
5	12
4	35
0	40
2	40
0	48
2	29
3	12
8	23
8	8
8	15
8	23
8	29
1	40
4	19
2	39
6	36
1	24
2	23
6	24
4	15
3	36
5	35
8	16
5	23
3	36
3	28
3	29
6	12
3	39
3	33
8	23
5	23
3	29
5	23
3	31
5	23
1	36
3	3
1	36
4	12
8	8
3	23
8	12
5	28
8	8
3	31
3	33
3	33
3	33
3	35
3	33
7	16
1	37
1	15
2	20
3	29
3	28
5	23
1	28
2	28
1	31
1	16
1	29
5	16
5	8
3	27
3	28
3	29
3	11
1	1
3	12
3	23
3	23
3	23
3	29
3	29
5	8
2	23
3	16
1	23
1	29
3	20
3	19
3	23
5	1
3	16
3	23
6	8
4	16
3	19
5	4
3	20
5	1
3	23
2	16
3	12
3	20
3	11
3	15