Riverside weather in August
In August, Riverside has daytime highs averaging 34 °C, nights around 20 °C, with 0.2 wet days. Figures are 1991–2020 climate normals.
- 34.1°C Average high
- 19.5°C Average low
- 0.2days Wet days
- 1mm Rainfall
- 13h Daylight
Daily temperatures through August
How August develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 August | 33.8 °C | 19.2 °C | 1 % |
| 11–20 August | 34.1 °C | 19.7 °C | 1 % |
| 21–31 August | 34.5 °C | 19.7 °C | 0 % |
What to expect
| Measure | Typical August | Share of the month |
|---|---|---|
| Days above 25 °C | 31 of 31 | 100 % |
| Days above 30 °C | 28 of 31 | 90 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 0.2 of 31 | 1 % |
Conditions in August
| Measure | Average |
|---|---|
| Mean temperature | 26 °C |
| Record high (1991–2020) | 44 °C |
| Record low (1991–2020) | 13 °C |
| Relative humidity | 52 % |
| Wind speed | 12 km/h |
| Cloud cover | 13 % |
Where Riverside ranks in August
| Ranking | Position | Value |
|---|---|---|
| The driest places in North America in August | 15th of 50 | 1.0 mm |
| The warmest places in North America in August | 29th of 50 | 34 °C |
August compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| June | 29.9 °C | 3 mm | 21 % |
| July | 33.0 °C | 2 mm | 18 % |
| August | 34.1 °C | 1 mm | 13 % |
| September | 32.5 °C | 5 mm | 17 % |
| October | 27.6 °C | 22 mm | 27 % |
See all twelve months for Riverside
- August is the warmest month in Riverside.
- It is the 1st driest month of the year.
- It ranks 1st for least cloud cover.
- Days last about 13 hours from sunrise to sunset.
- It rains on 0.2 of 31 days — 1 % of the month.
- Nights are about 15 °C cooler than the middle of the day.
- The hottest August day on record since 1991 reached 44 °C, 9.4 °C above the usual daytime high.
QuestionsAugust in Riverside, answered
How warm is Riverside in August?
Daily highs average 34 °C and nights fall to about 20 °C, a spread of 15 °C between afternoon and dawn. That makes August the 1st warmest month of the year here.
Does it rain much in Riverside in August?
August averages 1 mm of rain, spread over about 0 of the 31 days — 1 % of the month. Cloud cover averages 13 % of the sky.
How long are the days in August?
Riverside averages 13 hours between sunrise and sunset in August. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.