Climateby Month

Riverside, CA weather in August

NOAA 1991-2020 normals and daily records · Riverside all year

In August, Riverside sees highs around 95°F and lows around 65°F: hot and dry. Rain is rare. It is one of the warmest months in Riverside. Plan outdoor time for mornings and evenings.

Normal high
95°F
Normal low
65°F
Wet days
0
0.1 in total
Muggy days
0
dew point 65°F+

How August changes from start to finish

Normal values at the start and end of August
August 1August 31
Normal high95°F95°F
Normal low65°F64°F
Chance of a wet day1%1%
Sunrise / sunset6:01 am / 7:50 pm6:22 am / 7:17 pm
Daylight13.8 h12.9 h

Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).

A typical August day

  1. 6 am65°Fdew point 56°F
  2. 9 am81°Fdew point 55°F
  3. Noon92°Fdew point 52°F
  4. 3 pm93°Fdew point 53°F
  5. 6 pm84°Fdew point 53°F
  6. 9 pm73°Fdew point 55°F

NOAA hourly normals (local standard time) from March AFB (9 mi away); average wind 6 mph; clear or few clouds in 85% of daytime hours, mostly cloudy or overcast in 8%.

What kind of days to expect

  • Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
  • Hot dayshigh 90°F or more25 of 31
  • Muggy daysdaily mean dew point 65°F or more0 of 31
  • Wet daysat least 0.01 in of rain or melted snow0 of 31
  • Notable rainat least 0.10 in0 of 31
  • Freezing nightslow 32°F or below0 of 31

Average days per August, counted from daily records for each year 1991-2020.

Rain in August

Normal precipitation is 0.1 in; a dry August brings about 0.0 in and a wet one about 0.0 in (25th and 75th percentiles). Days with half an inch or more are rare.

How August varies from year to year

  • Warmest August, 1991-20201998: average high 98°F
  • Coolest August2004: average high 91°F
  • Wettest August2013: 1.1 in
  • Driest August1991: no measurable precipitation
  • Highest reading112°F (August 31, 2017)
  • Lowest reading53°F (August 31, 1999)

From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.

August compared with July and September

JulyAugustSeptember
Normal high93°F95°F91°F
Normal low64°F65°F62°F
Wet days100
Comfortable days004
Daylight14.2 h13.4 h12.4 h

Highs change by +2°F from July and -4°F into September.

Nearby alternatives in August

How Riverside ranks in August

  • Normal high54th warmest of 378 cities; 16th of 60 in California
  • Wet days34th driest of 378
  • Comfortable days230th most of 341

What to pack for Riverside in August

  • Light, breathable clothing – highs near 95°F
  • Layers – afternoons near 95°F but nights near 65°F

Heating and cooling

August has 0 heating degree days and 459 cooling degree days (base 65°F), 14% of the year's total heating and cooling demand.

Questions

How hot is Riverside in August?

The normal high is 95°F and the normal low is 65°F. From 1991 to 2020 the hottest August reading was 112°F (August 31, 2017).

Does it rain a lot in Riverside in August?

About 0 days in August have at least 0.01 in of precipitation, and the normal total is 0.1 in. The wettest August in 1991-2020 was in 2013 (1.1 in); the driest was in 1991, with no measurable precipitation.

Is August a good time to visit Riverside?

August ranks 12th of 12 months on our comfort score for Riverside (40 out of 100). It has almost no comfortable days and about 25 days at 90°F or hotter. The best months are March, April and May.

Where the numbers come from

  • Temperature and frost dates: Riverside Muni Airport (USW00003171), 2.4 mi W of the city center, 805 ft . NOAA normals and daily records, 1991-2020.
  • Rain, snowfall and snow depth: Riverside Fire Stn 3 (USC00047470), 0.5 mi ESE of the city center, 840 ft . NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour and cloud cover: March AFB (USW00023119), 9.2 mi ESE of the city center, 1,516 ft (687 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: March Air Reserve Base (722860-23119), 9.2 mi ESE of the city center, 1,536 ft (707 ft higher than the city). Hourly observations, 1991-2020.