Climate averages 1991–2020
Pomona weather
in April.
A warm, fairly dry month: the 7th warmest and the joint 7th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
April is a warm month in Pomona: daytime highs average 22.0°C and nights cool to about 9.7°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 25 mm of rain on roughly 4 days, which makes April a fairly dry month (the joint 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 01 min on an average April day.
The nearest other city in this atlas is Chino Hills (7 km away). In April its highs average 21.3°C, 0.6°C cooler than Pomona, with 25 mm of rain.
Among the 498 cities listed in the United States, Pomona ranks joint 161st of 498 for the warmest April highs and joint 69th of 498 for the driest April (rainfall, lowest first). The mean April high of those 498 cities is 19.4°C; Pomona is 2.6°C warmer than that mean.
From April to May, average highs rise by 2.1°C to 24.1°C, and monthly rainfall falls from 25 mm to 11 mm.
The annual picture
April in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Pomona climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 17.6°C6.4°C | 6.4°C | 93 | 5.9 | 10.210 h |
| February | 17.9°C6.7°C | 6.7°C | 102 | 6.6 | 10.911 h |
| March | 19.7°C8.2°C | 8.2°C | 62 | 6.2 | 12.012 h |
| April, selected | 22.0°C9.7°C | 9.7°C | 25 | 3.7 | 13.013 h |
| May | 24.1°C12.1°C | 12.1°C | 11 | 2.2 | 13.914 h |
| June | 27.5°C14.7°C | 14.7°C | 2.4 | 0.3 | 14.414 h |
| July | 30.9°C17.9°C | 17.9°C | 1.7 | 0.5 | 14.214 h |
| August | 32.1°C18.7°C | 18.7°C | 0.9 | 0.2 | 13.413 h |
| September | 30.7°C17.3°C | 17.3°C | 4.3 | 0.9 | 12.412 h |
| October | 26.3°C13.7°C | 13.7°C | 19 | 2.6 | 11.411 h |
| November | 21.6°C9.5°C | 9.5°C | 25 | 2.8 | 10.410 h |
| December | 17.3°C6.1°C | 6.1°C | 62 | 5.3 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
April in nearby cities
- Chino Hills in AprilUnited States · 7 kmHigh 21.3°C · Low 9.6°C · 25 mm rain
- Chino in AprilUnited States · 8 kmHigh 21.7°C · Low 9.8°C · 25 mm rain
- Ontario in AprilUnited States · 9 kmHigh 22.1°C · Low 9.8°C · 25 mm rain
- Rancho Cucamonga in AprilUnited States · 16 kmHigh 22.0°C · Low 9.4°C · 32 mm rain
- West Covina in AprilUnited States · 17 kmHigh 22.9°C · Low 10.2°C · 22 mm rain
- El Monte in AprilUnited States · 25 kmHigh 23.2°C · Low 10.4°C · 22 mm rain
- Fullerton in AprilUnited States · 26 kmHigh 22.5°C · Low 10.9°C · 18 mm rain
- Corona in AprilUnited States · 26 kmHigh 22.7°C · Low 10.4°C · 32 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Pomona) is explained once on the Pomona year overview and on the Sources, method and limits page.
Ontario, Chino and Chino Hills lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.