Hermiston weather in May

In May, Hermiston sees average daytime highs of 74°F and overnight lows near 51°F, with 0.9 in of rain across 5.4 wet days and about 14.7 hours of daylight. It is the 5th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 71°F in the first days to 77°F by the end. The sky is clear or mostly clear about 34% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 h 06 min at the start of May to 15 h 12 min by month's end. Set against the rest of the year, May is Hermiston's 6th-clearest and 3rd-windiest month. For the whole year in context, see Hermiston's year-round climate.

Daytime high: 74°; 5th warmest
Overnight low: 51°; 8th coldest
Rainfall: 0.9 in; 5.4 wet days
Daylight: 14 h 42 min; 4:32 AM – 7:15 PM
Cloud cover: 54%; 6th clearest
Wind: 8 mph; 3rd windiest
Solar energy: 6.74 kWh/m²
Travel score: 7.6; out of 10

Hermiston is city in Oregon, USA.

Density: 815/km²; people per km²
Founded: 1907

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← April Hermiston year-round climate June →Best places to visit in May

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 71°F in the first days to 77°F by the end.

A typical May day in Hermiston reaches about 74°F in the afternoon and slips back to 51°F overnight — a 23°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 88°F. Set against its neighbours, May runs about 10°F warmer than April and about 7°F cooler than June.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°F)	70	70	71	71	71	71	72	72	73	73	73	73	74	74	74	74	75	75	75	75	76	76	76	76	76	77	77	77	77	78	78
Avg low (°F)	47	47	47	47	48	48	48	49	49	49	50	50	50	51	51	51	51	52	52	52	52	53	53	53	53	53	54	54	54	54	54

	Avg high (°F)	Avg low (°F)
1	70	47
2	70	47
3	71	47
4	71	47
5	71	48
6	71	48
7	72	48
8	72	49
9	73	49
10	73	49
11	73	50
12	73	50
13	74	50
14	74	51
15	74	51
16	74	51
17	75	51
18	75	52
19	75	52
20	75	52
21	76	52
22	76	53
23	76	53
24	76	53
25	76	53
26	77	53
27	77	54
28	77	54
29	77	54
30	78	54
31	78	54

How May really feels in Hermiston

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F

heat index over the day's high

Days feeling ≤ 32°F

wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Hermiston weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 8th-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	42° / 31°	1.5	9.5	2.2	8.9	0.3
Feb	48° / 33°	1.2	7.7	1.5	10.1	1.8
Mar	56° / 38°	1.3	8.3	0.3	11.6	4.0
Apr	65° / 44°	1.0	6.3	0	13.3	6.2
May	74° / 51°	0.9	5.4	0	14.7	7.6
Jun	81° / 57°	0.6	3.3	0	15.5	7.4
Jul	91° / 63°	0.1	1	0	15.2	4.9
Aug	89° / 62°	0.2	1	0	13.9	5.3
Sep	79° / 55°	0.3	2.2	0	12.3	8.1
Oct	65° / 45°	1.0	5.9	0.1	10.7	6.5
Nov	50° / 36°	1.4	8.7	0.7	9.3	2.3
Dec	42° / 31°	1.6	9.6	2.6	8.5	0.2

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 19% of May, with mostly cloudy or overcast conditions the remaining 47%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	55	55	55	56	56	55	55	54	53	52	51	51	50	50	49	49	49	49	50	50	50	51	52	53	54	54	55	55	56	57	57
Cloudier (%)	45	45	45	44	44	45	45	46	47	48	49	49	50	50	51	51	51	51	50	50	50	49	48	47	46	46	45	45	44	43	43

	Clearer (%)	Cloudier (%)
1	55	45
2	55	45
3	55	45
4	56	44
5	56	44
6	55	45
7	55	45
8	54	46
9	53	47
10	52	48
11	51	49
12	51	49
13	50	50
14	50	50
15	49	51
16	49	51
17	49	51
18	49	51
19	50	50
20	50	50
21	50	50
22	51	49
23	52	48
24	53	47
25	54	46
26	54	46
27	55	45
28	55	45
29	56	44
30	57	43
31	57	43

Chance of precipitation in May

Any precipitation

Hermiston gets around 0.9 in of rain over 5.4 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 17% and peaks near 19% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	16	16	15	15	15	16	16	16	17	17	18	18	18	19	19	19	19	19	19	19	19	19	18	18	18	17	17	16	16	16	16

	Rain chance (%)
1	16
2	16
3	15
4	15
5	15
6	16
7	16
8	16
9	17
10	17
11	18
12	18
13	18
14	19
15	19
16	19
17	19
18	19
19	19
20	19
21	19
22	19
23	18
24	18
25	18
26	17
27	17
28	16
29	16
30	16
31	16

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	99	99	99	99	99	99	99	99
Comfortable (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1	1	1	1	1	1	1

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	100	0
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	99	1
31	99	1

Wind in May

Winds average 8 mph in May.

Across May, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (mph)	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

	Wind speed (mph)	Feels
1	8	light breeze
2	8	light breeze
3	8	light breeze
4	8	light breeze
5	8	light breeze
6	8	light breeze
7	8	light breeze
8	8	light breeze
9	8	light breeze
10	8	light breeze
11	8	light breeze
12	8	light breeze
13	8	light breeze
14	8	light breeze
15	8	light breeze
16	8	light breeze
17	8	light breeze
18	8	light breeze
19	8	light breeze
20	8	light breeze
21	8	light breeze
22	8	light breeze
23	8	light breeze
24	8	light breeze
25	8	light breeze
26	8	light breeze
27	8	light breeze
28	8	light breeze
29	8	light breeze
30	8	light breeze
31	8	light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 14 h 06 min at the start of May to 15 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over May. Sunrise moves from 4:53 AM to 4:18 AM, and sunset from 6:56 PM to 7:31 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	14.1	14.1	14.2	14.2	14.2	14.3	14.3	14.4	14.4	14.5	14.5	14.6	14.6	14.6	14.7	14.7	14.8	14.8	14.8	14.9	14.9	14.9	15.0	15.0	15.0	15.1	15.1	15.1	15.2	15.2	15.2
Sunrise (AM)	4:53	4:51	4:49	4:48	4:46	4:45	4:44	4:42	4:41	4:39	4:38	4:37	4:35	4:34	4:33	4:32	4:31	4:29	4:28	4:27	4:26	4:25	4:24	4:23	4:22	4:22	4:21	4:20	4:19	4:18	4:18
Sunset (PM)	6:56	6:57	6:59	7:00	7:01	7:03	7:04	7:05	7:06	7:08	7:09	7:10	7:11	7:13	7:14	7:15	7:16	7:17	7:19	7:20	7:21	7:22	7:23	7:24	7:25	7:26	7:27	7:28	7:29	7:30	7:31

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	14.1	4:53	6:56
2	14.1	4:51	6:57
3	14.2	4:49	6:59
4	14.2	4:48	7:00
5	14.2	4:46	7:01
6	14.3	4:45	7:03
7	14.3	4:44	7:04
8	14.4	4:42	7:05
9	14.4	4:41	7:06
10	14.5	4:39	7:08
11	14.5	4:38	7:09
12	14.6	4:37	7:10
13	14.6	4:35	7:11
14	14.6	4:34	7:13
15	14.7	4:33	7:14
16	14.7	4:32	7:15
17	14.8	4:31	7:16
18	14.8	4:29	7:17
19	14.8	4:28	7:19
20	14.9	4:27	7:20
21	14.9	4:26	7:21
22	14.9	4:25	7:22
23	15.0	4:24	7:23
24	15.0	4:23	7:24
25	15.0	4:22	7:25
26	15.1	4:22	7:26
27	15.1	4:21	7:27
28	15.1	4:20	7:28
29	15.2	4:19	7:29
30	15.2	4:18	7:30
31	15.2	4:18	7:31

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.74 kWh/m².

For context, solar energy here swings from a low near 1.29 kWh/m² to a high of 7.88 kWh/m² in July across the year — May's 6.74 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	6.4	6.4	6.5	6.5	6.5	6.5	6.6	6.6	6.6	6.6	6.6	6.6	6.7	6.7	6.7	6.7	6.7	6.7	6.8	6.8	6.8	6.8	6.9	6.9	6.9	7.0	7.0	7.0	7.0	7.1	7.1
Level	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense

	Solar energy (kWh/m²)	Level
1	6.4	Intense
2	6.4	Intense
3	6.5	Intense
4	6.5	Intense
5	6.5	Intense
6	6.5	Intense
7	6.6	Intense
8	6.6	Intense
9	6.6	Intense
10	6.6	Intense
11	6.6	Intense
12	6.6	Intense
13	6.7	Intense
14	6.7	Intense
15	6.7	Intense
16	6.7	Intense
17	6.7	Intense
18	6.7	Intense
19	6.8	Intense
20	6.8	Intense
21	6.8	Intense
22	6.8	Intense
23	6.9	Intense
24	6.9	Intense
25	6.9	Intense
26	7.0	Intense
27	7.0	Intense
28	7.0	Intense
29	7.0	Intense
30	7.1	Intense
31	7.1	Intense

Planning a trip in May

Is May a good time to visit Hermiston?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.6

Sightseeing

2nd-best month of the year

6.0

Beach & pool

5th-best month of the year

May is one of the better times to visit Hermiston for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Hermiston in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Hermiston sees daytime highs around 74°F and nights near 51°F. Pack sun protection. Worth having: light clothes. About 5 days see rain.

sun protectionlight clothes

UV index in Hermiston in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hermiston peaks around July 16 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	1	2	4	5	7	7	8	6	5	4	1	1
Level	Low	Low	Moderate	Moderate	Very high	High	Very high	High	Moderate	Moderate	Low	Low

	UV index (midday)	Level
Jan	1	Low
Feb	2	Low
Mar	4	Moderate
Apr	5	Moderate
May	7	Very high
Jun	7	High
Jul	8	Very high
Aug	6	High
Sep	5	Moderate
Oct	4	Moderate
Nov	1	Low
Dec	1	Low

Air quality in Hermiston in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Hermiston is worst in August — around 25 µg/m³ PM2.5 (moderate), about 3.5× the cleanest month (December, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	8	9	11	10	9	9	15	25	20	11	10	7
Level	Good	Good	Good	Good	Good	Good	Moderate	Moderate	Moderate	Good	Good	Good

	PM2.5 (µg/m³)	Level
Jan	8	Good
Feb	9	Good
Mar	11	Good
Apr	10	Good
May	9	Good
Jun	9	Good
Jul	15	Moderate
Aug	25	Moderate
Sep	20	Moderate
Oct	11	Good
Nov	10	Good
Dec	7	Good

Location & terrain

Where is Hermiston?

Hermiston sits at 45.8°N, 119.3°W, 459 ft above sea level, in United States. The nearest listed city is Kennewick, 27 mi away.

Topography around Hermiston

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Hermiston.

Within 2 miles, the terrain around Hermiston has only modest variations in elevation — a maximum elevation change of 236 ft around an average of 509 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 932 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,659 ft.

The land around Hermiston is covered by grassland (45%) and artificial surfaces (29%) within 2 miles, grassland (45%) and cropland (41%) within 10 miles, and grassland (54%) and cropland (35%) within 50 miles.

2 miles

236 ft

grassland 45%

10 miles

932 ft

grassland 45%

50 miles

5,659 ft

grassland 54%

treesgrasslandcroplandartificial surfacesbare terrainwater

← April Hermiston year-round climate June →Best places to visit in May

May weather nearby: Kennewick 27 mi · Pendleton 27 mi · Tri-Cities 29 mi · Pasco 29 mi · Richland 31 mi · Sunnyside 48 mi · Walla Walla 48 mi · Yakima 78 mi

United States travel facts

Power plugs: Type A / B; 120 V · 60 Hz
Prices: ≈ 100% of US; price level, 2025
GDP per capita: $90,027; 2025
Happiness: 6.8 / 10; World Happiness, 2025
Safe drinking water: 98%; of population, 2024
Homicide rate: 5.8; per 100k, 2023
Road deaths: 12.7; per 100k/yr, 2019
Income group: High; World Bank
Religion

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hermiston (45.8404°, -119.2895°, elevation 459 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°F)	Avg low (°F)
1	70	47
2	70	47
3	71	47
4	71	47
5	71	48
6	71	48
7	72	48
8	72	49
9	73	49
10	73	49
11	73	50
12	73	50
13	74	50
14	74	51
15	74	51
16	74	51
17	75	51
18	75	52
19	75	52
20	75	52
21	76	52
22	76	53
23	76	53
24	76	53
25	76	53
26	77	53
27	77	54
28	77	54
29	77	54
30	78	54
31	78	54

	Clearer (%)	Cloudier (%)
1	55	45
2	55	45
3	55	45
4	56	44
5	56	44
6	55	45
7	55	45
8	54	46
9	53	47
10	52	48
11	51	49
12	51	49
13	50	50
14	50	50
15	49	51
16	49	51
17	49	51
18	49	51
19	50	50
20	50	50
21	50	50
22	51	49
23	52	48
24	53	47
25	54	46
26	54	46
27	55	45
28	55	45
29	56	44
30	57	43
31	57	43

	Rain chance (%)
1	16
2	16
3	15
4	15
5	15
6	16
7	16
8	16
9	17
10	17
11	18
12	18
13	18
14	19
15	19
16	19
17	19
18	19
19	19
20	19
21	19
22	19
23	18
24	18
25	18
26	17
27	17
28	16
29	16
30	16
31	16

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	100	0
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	99	1
31	99	1

	Avg high (°F)	Avg low (°F)
1	70	47
2	70	47
3	71	47
4	71	47
5	71	48
6	71	48
7	72	48
8	72	49
9	73	49
10	73	49
11	73	50
12	73	50
13	74	50
14	74	51
15	74	51
16	74	51
17	75	51
18	75	52
19	75	52
20	75	52
21	76	52
22	76	53
23	76	53
24	76	53
25	76	53
26	77	53
27	77	54
28	77	54
29	77	54
30	78	54
31	78	54

	Clearer (%)	Cloudier (%)
1	55	45
2	55	45
3	55	45
4	56	44
5	56	44
6	55	45
7	55	45
8	54	46
9	53	47
10	52	48
11	51	49
12	51	49
13	50	50
14	50	50
15	49	51
16	49	51
17	49	51
18	49	51
19	50	50
20	50	50
21	50	50
22	51	49
23	52	48
24	53	47
25	54	46
26	54	46
27	55	45
28	55	45
29	56	44
30	57	43
31	57	43

	Rain chance (%)
1	16
2	16
3	15
4	15
5	15
6	16
7	16
8	16
9	17
10	17
11	18
12	18
13	18
14	19
15	19
16	19
17	19
18	19
19	19
20	19
21	19
22	19
23	18
24	18
25	18
26	17
27	17
28	16
29	16
30	16
31	16

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	100	0
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	99	1
31	99	1

	Avg high (°F)	Avg low (°F)
1	70	47
2	70	47
3	71	47
4	71	47
5	71	48
6	71	48
7	72	48
8	72	49
9	73	49
10	73	49
11	73	50
12	73	50
13	74	50
14	74	51
15	74	51
16	74	51
17	75	51
18	75	52
19	75	52
20	75	52
21	76	52
22	76	53
23	76	53
24	76	53
25	76	53
26	77	53
27	77	54
28	77	54
29	77	54
30	78	54
31	78	54

	Clearer (%)	Cloudier (%)
1	55	45
2	55	45
3	55	45
4	56	44
5	56	44
6	55	45
7	55	45
8	54	46
9	53	47
10	52	48
11	51	49
12	51	49
13	50	50
14	50	50
15	49	51
16	49	51
17	49	51
18	49	51
19	50	50
20	50	50
21	50	50
22	51	49
23	52	48
24	53	47
25	54	46
26	54	46
27	55	45
28	55	45
29	56	44
30	57	43
31	57	43

	Rain chance (%)
1	16
2	16
3	15
4	15
5	15
6	16
7	16
8	16
9	17
10	17
11	18
12	18
13	18
14	19
15	19
16	19
17	19
18	19
19	19
20	19
21	19
22	19
23	18
24	18
25	18
26	17
27	17
28	16
29	16
30	16
31	16

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	100	0
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	99	1
31	99	1