Fullerton weather in August: Fullerton, California: normal highs, lows, rain and records for August
Fullerton in August has a normal high of 87°F and a normal low of 66°F, a daily mean of 77°F, rising from 86°F on the 1st to 87°F by the 31st. Measurable precipitation falls on 0 days in a normal August, 0.02 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 30°C and low of 19°C, 1 mm of precipitation in August.
- NOAA stationFullerton Municipal Airport
- Station IDUSW00003166
- Location33.87°N 117.98°W
- Elevation96 ft (29 m)
- From the center3 miles
- Population140,054
- Jan 69° 46°
- Feb 69° 48°
- Mar 71° 52°
- Apr 74° 54°
- May 76° 58°
- Jun 79° 63°
- Jul 84° 66°
- Aug 87° 66°
- Sep 85° 65°
- Oct 80° 58°
- Nov 74° 51°
- Dec 68° 46°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Fullerton in August?
The normal high is 87°F and the normal low 66°F, for a daily mean of 76.5°F. August is 1.3°F warmer than July and 1.5°F warmer than September. August is the warmest month of the year in Fullerton and the 11th wettest. Across the month the normal high rises 1°F, from 86°F on August 1 to 87°F on August 31. From one year to the next August's mean temperature typically moves about 2.5°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 74°F and 79°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 1%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 86°F | 67°F | 1% | – |
| August 8 | 86°F | 66°F | 1% | – |
| August 15 | 87°F | 66°F | 1% | – |
| August 22 | 87°F | 66°F | 1% | – |
| August 31 | 87°F | 66°F | 1% | – |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 26, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 86°F | 67°F | 1% | – | 13 h 50 min |
| August 2 | 86°F | 67°F | 1% | – | 13 h 50 min |
| August 3 | 86°F | 67°F | 1% | – | 13 h 50 min |
| August 4 | 86°F | 67°F | 1% | – | 13 h 50 min |
| August 5 | 86°F | 67°F | 1% | – | 13 h 40 min |
| August 6 | 86°F | 67°F | 1% | – | 13 h 40 min |
| August 7 | 86°F | 67°F | 1% | – | 13 h 40 min |
| August 8 | 86°F | 66°F | 1% | – | 13 h 40 min |
| August 9 | 86°F | 66°F | 1% | – | 13 h 40 min |
| August 10 | 86°F | 66°F | 1% | – | 13 h 40 min |
| August 11 | 86°F | 66°F | 1% | – | 13 h 30 min |
| August 12 | 87°F | 66°F | 1% | – | 13 h 30 min |
| August 13 | 87°F | 66°F | 1% | – | 13 h 30 min |
| August 14 | 87°F | 66°F | 1% | – | 13 h 30 min |
| August 15 | 87°F | 66°F | 1% | – | 13 h 30 min |
| August 16 | 87°F | 66°F | 1% | – | 13 h 30 min |
| August 17 | 87°F | 66°F | 1% | – | 13 h 20 min |
| August 18 | 87°F | 66°F | 1% | – | 13 h 20 min |
| August 19 | 87°F | 66°F | 1% | – | 13 h 20 min |
| August 20 | 87°F | 66°F | 1% | – | 13 h 20 min |
| August 21 | 87°F | 66°F | 1% | – | 13 h 20 min |
| August 22 | 87°F | 66°F | 1% | – | 13 h 10 min |
| August 23 | 87°F | 66°F | 1% | – | 13 h 10 min |
| August 24 | 87°F | 66°F | 1% | – | 13 h 10 min |
| August 25 | 87°F | 66°F | 1% | – | 13 h 10 min |
| August 26 | 87°F | 66°F | 1% | – | 13 h 10 min |
| August 27 | 87°F | 66°F | 1% | – | 13 h |
| August 28 | 87°F | 66°F | 1% | – | 13 h |
| August 29 | 87°F | 66°F | 1% | – | 13 h |
| August 30 | 87°F | 66°F | 1% | – | 13 h |
| August 31 | 87°F | 66°F | 1% | – | 13 h |
- Normal high
- 87°FAugust average
- Normal low
- 66°FAugust average
- Precipitation
- 0.02 inmonth total
- Days with precipitation
- fewer than 10.01 inch or more
- Days at 90°F or more
- 9
- Daylight
- 13 h 50 min to 13 hAugust 1 to August 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 28
- Sunshine
- 92%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003166; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Fullerton in August?
On a given August day the chance of 0.01 inch or more is 1% on average, highest around August 31 (1%). In all, 0.02 in falls on 0 days of a normal August.
In a normal August in Fullerton, 9 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003166.
What are the records for August in Fullerton?
The warmest August temperature on this station's record (since 1998) is 107°F, on August 27, 2009; the coldest is 56°F, on August 12, 2010. The wettest August brought 2.20 in (2023).
The August mean against the 1991-2020 normal of 76.5°F: 2021 77.2°F (+0.7), 2022 79.2°F (+2.7), 2023 77.0°F (+0.5), 2024 76.8°F (+0.3), 2025 76.6°F (+0.1), 2026 80.8°F (+4.3). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 77.2°F | +0.7°F | 0.02 in |
| 2022 | 79.2°F | +2.7°F | 0.00 in |
| 2023 | 77.0°F | +0.5°F | 2.20 in |
| 2024 | 76.8°F | +0.3°F | 0.00 in |
| 2025 | 76.6°F | +0.1°F | 0.00 in |
| 2026 | 80.8°F | +4.3°F | 0.00 in |
Source: records: ACIS, station USW00003166; recent months: ACIS, station USW00003166. Records and recent months use complete months only.
How does August in Fullerton compare across California?
Across the 219 places PlainClimate covers in California, August normal highs run from 63°F in Bodega to 109°F in Needles; Fullerton's is 87°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.