Portola Valley Weather in August
Average highs run from 81°F on August 1 to 81°F on August 31, and lows from 57°F to 56°F. Normal precipitation for the month is 0.04 in over about 0 wet days.
August day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
August at a glance
- Average high
- 81°F
- Average low
- 57°F
- Precipitation
- 0.04 in
- Record high
- 101°FAug 30, 1968
- Record low
- 44°FAug 4, 1982
- Chance of a freeze
- 0%
- Days of 90°F or more
- 3.8
- Daylight
- 14 h 03 min to 13 h 00 min
- Cloud cover
- 14%
- Humidity
- 62%
- Dew point
- 50°F
- Wind
- 8.3 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Aug 1 | 81°F | 57°F | 94°F 1977 | 48°F 1982 | 0% | 0% |
| Aug 2 | 81°F | 57°F | 95°F 1975 | 46°F 1956 | 0% | 0% |
| Aug 3 | 81°F | 57°F | 94°F 1998 | 48°F 1956 | 0% | 0% |
| Aug 4 | 81°F | 57°F | 100°F 1998 | 44°F 1982 | 0% | 0% |
| Aug 5 | 81°F | 57°F | 90°F 1969 | 47°F 1954 | 0% | 0% |
| Aug 6 | 81°F | 57°F | 94°F 1998 | 50°F 1959 | 1% | 0% |
| Aug 7 | 81°F | 57°F | 96°F 1983 | 47°F 1975 | 1% | 0% |
| Aug 8 | 81°F | 57°F | 97°F 1984 | 50°F 1969 | 1% | 0% |
| Aug 9 | 81°F | 57°F | 94°F 1975 | 50°F 1976 | 1% | 0% |
| Aug 10 | 81°F | 57°F | 97°F 1970 | 50°F 2008 | 1% | 0% |
| Aug 11 | 81°F | 57°F | 95°F 2006 | 47°F 1982 | 1% | 0% |
| Aug 12 | 81°F | 57°F | 95°F 1959 | 48°F 1957 | 1% | 0% |
| Aug 13 | 81°F | 57°F | 97°F 1959 | 48°F 2007 | 1% | 0% |
| Aug 14 | 81°F | 57°F | 93°F 1995 | 48°F 2007 | 1% | 0% |
| Aug 15 | 81°F | 57°F | 96°F 2015 | 48°F 1954 | 1% | 0% |
| Aug 16 | 81°F | 57°F | 96°F 2015 | 49°F 1954 | 1% | 0% |
| Aug 17 | 81°F | 57°F | 98°F 2015 | 48°F 2017 | 1% | 0% |
| Aug 18 | 81°F | 56°F | 90°F 1988 | 49°F 1963 | 1% | 0% |
| Aug 19 | 81°F | 56°F | 90°F 1978 | 49°F 1964 | 1% | 0% |
| Aug 20 | 81°F | 56°F | 95°F 1995 | 47°F 1977 | 1% | 0% |
| Aug 21 | 81°F | 56°F | 90°F 1964 | 47°F 1959 | 1% | 0% |
| Aug 22 | 81°F | 56°F | 89°F 1969 | 46°F 1973 | 1% | 0% |
| Aug 23 | 81°F | 56°F | 89°F 1959 | 48°F 2010 | 1% | 0% |
| Aug 24 | 81°F | 56°F | 93°F 2010 | 47°F 1955 | 1% | 0% |
| Aug 25 | 81°F | 56°F | 100°F 2010 | 45°F 1963 | 1% | 0% |
| Aug 26 | 81°F | 56°F | 97°F 1988 | 46°F 1963 | 1% | 0% |
| Aug 27 | 81°F | 56°F | 89°F 1976 | 45°F 1960 | 1% | 0% |
| Aug 28 | 81°F | 56°F | 98°F 2009 | 47°F 2016 | 1% | 0% |
| Aug 29 | 81°F | 56°F | 100°F 2008 | 48°F 1964 | 1% | 0% |
| Aug 30 | 81°F | 56°F | 101°F 1968 | 45°F 1955 | 1% | 0% |
| Aug 31 | 81°F | 56°F | 94°F 1996 | 46°F 1969 | 1% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- August 1
- sunrise 6:14 AM, sunset 8:17 PM
- August 31
- sunrise 6:39 AM, sunset 7:39 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00047339 (Redwood City), public domain. Records: NOAA GHCN-Daily, station USC00046646, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.