Pomona weather in May

In May, Pomona sees average daytime highs of 74°F and overnight lows near 55°F, with 0.4 in of rain across 2.2 wet days and about 13.7 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 74°F through the month. The sky is clear or mostly clear about 63% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of May to 14 h 06 min by month's end. Set against the rest of the year, May is Pomona's 6th-clearest and 1st-windiest month. For the whole year in context, see Pomona's year-round climate.

Daytime high
74°
6th warmest
Overnight low
55°
7th coldest
Rainfall
0.4 in
2.2 wet days
Daylight
13 h 48 min
4:54 AM – 6:40 PM
Cloud cover
33%
6th clearest
Wind
4 mph
1st windiest
Solar energy
7.32 kWh/m²
Travel score
8.6
out of 10

Pomona is city in Los Angeles County, California, United States.

Density
2,577/km²
people per km²
Founded
1888

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 74°F through the month.

A typical May day in Pomona reaches about 74°F in the afternoon and slips back to 55°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 64°F and 84°F. Set against its neighbours, May runs about 4°F warmer than April and about 6°F cooler than June.

40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17353
27353
37353
47354
57354
67354
77354
87354
97354
107354
117354
127354
137355
147355
157355
167355
177355
187355
197455
207455
217455
227455
237455
247455
257456
267456
277556
287556
297556
307556
317656

Pomona weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan63° / 44°3.65.9106.2
Feb63° / 46°4.06.610.76.2
Mar66° / 48°2.46.311.76.8
Apr70° / 51°1.03.712.87.8
May74° / 55°0.42.213.78.6
Jun79° / 59°0.10.314.28.9
Jul85° / 64°0.10.5147.1
Aug87° / 65°0.00.213.36.5
Sep84° / 63°0.20.912.27.4
Oct78° / 57°0.72.611.18.7
Nov69° / 49°1.02.810.28.0
Dec62° / 44°2.55.39.86.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 63% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 12% of May, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17129
27129
37129
47129
57129
67129
77129
87129
97129
107228
117228
127327
137327
147426
157525
167525
177525
187624
197624
207723
217723
227723
237921
247921
257921
268119
278119
288119
298218
308218
318416

Chance of precipitation in May

Any precipitation

Pomona gets around 0.4 in of rain over 2.2 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 7% and peaks near 10% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202531
Rain chance (%)
110
210
310
410
59
69
79
89
99
109
119
128
138
148
158
167
177
187
197
207
216
226
236
245
255
265
274
284
293
303
313

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 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19370
29370
39370
49280
59280
69190
79190
890100
989110
1089110
1188120
1287130
1386140
1485150
1584160
1683170
1783170
1882180
1981190
2081190
2180200
2278211
2377221
2476231
2575241
2674251
2773261
2872271
2971281
3070291
3169301

Wind in May

Winds average 4 mph in May, the windiest month of the year.

Across May, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 18 min at the start of May to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over May. Sunrise moves from 5:08 AM to 4:46 AM, and sunset from 6:28 PM to 6:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:086:28
213.45:076:29
313.45:066:30
413.45:056:31
513.55:046:32
613.55:036:32
713.55:026:33
813.65:016:34
913.65:006:35
1013.64:596:36
1113.64:586:36
1213.74:576:37
1313.74:576:38
1413.74:566:39
1513.74:556:39
1613.84:546:40
1713.84:546:41
1813.84:536:42
1913.84:526:42
2013.94:526:43
2113.94:516:44
2213.94:506:45
2313.94:506:45
2413.94:496:46
2514.04:496:47
2614.04:486:48
2714.04:486:48
2814.04:476:49
2914.04:476:50
3014.14:466:50
3114.14:466:51

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 7.32 kWh/m².

For context, solar energy here swings from a low near 2.95 kWh/m² to a high of 8.05 kWh/m² in June across the year — May's 7.32 kWh/m² falls in the middle.

02468151015202531
Solar energy (kWh/m²)Level
17.0Intense
27.1Intense
37.1Intense
47.1Intense
57.1Intense
67.1Intense
77.1Intense
87.2Intense
97.2Intense
107.2Intense
117.2Intense
127.2Intense
137.3Intense
147.3Intense
157.3Intense
167.3Intense
177.3Intense
187.3Intense
197.4Intense
207.4Intense
217.4Intense
227.4Intense
237.5Intense
247.5Intense
257.5Intense
267.5Intense
277.6Intense
287.6Intense
297.6Intense
307.7Intense
317.7Intense
Planning a trip in May

Is May a good time to visit Pomona?

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

8.6
Sightseeing
3rd-best month of the year
6.8
Beach & pool
6th-best month of the year

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

What to pack for Pomona in May

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

In May, Pomona sees daytime highs around 74°F and nights near 55°F. Pack sun protection. Worth having: light clothes.

sun protectionlight clothes

Sea temperature near Pomona in May

The nearest coast averages about 63°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 30 mi away) is warmest in August at about 69°F and coldest in February near 59°F.

It's comfortable for a long swim from Jul 13 to Sep 28 — about 2.6 months when the water holds above 68°F.

60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°F)Comfort
Jan59Cool
Feb59Cool
Mar59Cool
Apr60Cool
May63Cool
Jun65Cool
Jul68Refreshing
Aug69Refreshing
Sep69Refreshing
Oct67Cool
Nov64Cool
Dec60Cool

UV index in Pomona in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Pomona peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 12UV 11Dec 16UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Pomona 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 Pomona is worst in September — around 49 µg/m³ PM2.5 (poor), about 4.0× the cleanest month (May, 12 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateSep 1447 µg/m³May 1713 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb19Moderate
Mar19Moderate
Apr17Moderate
May12Moderate
Jun17Moderate
Jul19Moderate
Aug32Moderate
Sep49Poor
Oct21Moderate
Nov21Moderate
Dec18Moderate
Location & terrain

Where is Pomona?

Pomona sits at 34.1°N, 117.8°W, 850 ft above sea level, in United States. The nearest listed city is La Verne, 3.1 mi away.

Topography around Pomona

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

Within 2 miles, the terrain around Pomona has only modest variations in elevation — a maximum elevation change of 505 ft around an average of 869 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 5,085 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 10,732 ft.

The land around Pomona is covered by artificial surfaces (85%) within 2 miles, artificial surfaces (53%) within 10 miles, and artificial surfaces (27%) and shrubs (20%) within 50 miles.

2 miles
505 ft
10 miles
5,085 ft
50 miles
10,732 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: La Verne 3.1 mi · Claremont 3.1 mi · Diamond Bar 3.7 mi · Montclair 3.7 mi · Chino Hills 4.3 mi · Chino 5.0 mi · San Dimas 5.0 mi · Ontario 5.6 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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 Pomona (34.0553°, -117.7523°, elevation 850 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).