Climate averages 1991–2020
Boise weather
in April.
A mild, fairly dry month: the 7th warmest and the joint 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
April is a mild month in Boise: daytime highs average 15.9°C and nights cool to about 3.8°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 31 mm of rain on roughly 7 days, which makes April a fairly dry month (the joint 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 24 min on an average April day.
The nearest other city in this atlas is Meridian (15 km away). In April its highs average 16.1°C, about as warm as Boise, with 28 mm of rain.
Among the 498 cities listed in the United States, Boise ranks joint 338th of 498 for the warmest April highs and joint 88th of 498 for the driest April (rainfall, lowest first). The mean April high of those 498 cities is 19.4°C; Boise is 3.5°C cooler than that mean.
From April to May, average highs rise by 5.7°C to 21.6°C, and monthly rainfall stays at 31 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
Boise climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 3.8°C-4.6°C | -4.6°C | 45 | 9.5 | 9.39 h |
| February | 6.8°C-2.5°C | -2.5°C | 31 | 7.7 | 10.510 h |
| March | 11.9°C0.9°C | 0.9°C | 36 | 8.9 | 11.912 h |
| April, selected | 15.9°C3.8°C | 3.8°C | 31 | 7.2 | 13.413 h |
| May | 21.6°C8.5°C | 8.5°C | 31 | 5.9 | 14.715 h |
| June | 26.5°C13.0°C | 13.0°C | 16 | 3.2 | 15.415 h |
| July | 32.7°C17.9°C | 17.9°C | 2.6 | 0.9 | 15.115 h |
| August | 31.9°C17.4°C | 17.4°C | 3.3 | 0.7 | 14.014 h |
| September | 26.2°C12.6°C | 12.6°C | 10 | 2.2 | 12.613 h |
| October | 17.7°C6.3°C | 6.3°C | 22 | 4.3 | 11.111 h |
| November | 9.3°C0.2°C | 0.2°C | 34 | 7.9 | 9.710 h |
| December | 3.7°C-4.1°C | -4.1°C | 50 | 10.1 | 9.09 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
- Meridian in AprilUnited States · 15 kmHigh 16.1°C · Low 3.8°C · 28 mm rain
- Nampa in AprilUnited States · 30 kmHigh 16.8°C · Low 4.7°C · 28 mm rain
- Kennewick in AprilUnited States · 370 kmHigh 19.1°C · Low 6.5°C · 17 mm rain
- Tri-Cities in AprilUnited States · 376 kmHigh 19.3°C · Low 6.6°C · 17 mm rain
- Missoula in AprilUnited States · 401 kmHigh 11.4°C · Low 1.5°C · 53 mm rain
- Bend in AprilUnited States · 413 kmHigh 11.7°C · Low 0.2°C · 46 mm rain
- Ogden in AprilUnited States · 437 kmHigh 13.6°C · Low 2.4°C · 64 mm rain
- Layton in AprilUnited States · 449 kmHigh 13.5°C · Low 2.3°C · 63 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 Boise) is explained once on the Boise year overview and on the Sources, method and limits page.