Hottest (avg)
#2 / 12
One of the warmer months.
August in context
How it compares to the rest of the year in San Francisco.
Wettest (avg)
#11 / 12
One of the drier months.
Daylight Hours
#4 / 12
Around the yearly average.
Windiest (avg)
#6 / 12
Close to the yearly wind average.
Highest UV
#4 / 12
Near the middle of the yearly UV range.
Most Humid
#6 / 12
Humidity stays close to the yearly norm.
Monthly climate breakdown
A detailed look at the typical climate conditions for August.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
13.6 h
Average daylight
- UV index (max)
- 8
- Typical sun hours
- 05:25 - 19:00
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 0 days
- Cloud cover (avg)
- 43%
Air feel
Humidity & Wind
78%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through August in San Francisco. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Median temperatureMedian lowTypical range
Day 15 selected for August. Temperature 21.4°C.
Historical disruption baseline
Typical disruptions in August
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in August.
Show all disruptions (11)
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 1% of days (0.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~68km/h (P95)
Why this matters
Strong gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heat Moderate
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~34°C (P95)
Why this matters
Feels-like heat >=32C is possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 51% of days (15.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
15.7 days / month
- Share of days
- ~51% of days
- Upper edge
- Up to ~57km/h (P95)
Why this matters
Gusty conditions are possible on ~16 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 42% of days (13.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
13.1 days / month
- Share of days
- ~42% of days
- Upper edge
- Up to ~89% (P95)
Why this matters
High humidity is possible on ~13 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 22% of days (6.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
6.7 days / month
- Share of days
- ~22% of days
- Upper edge
- Up to ~97% (P95)
Why this matters
Cloudy skies are possible on ~7 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 9% of days (2.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.8 days / month
- Share of days
- ~9% of days
- Upper edge
- Up to ~99% (P95)
Why this matters
Mostly cloudy skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 4% of days (1.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.1 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~29km/h (P95)
Why this matters
Breezy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 4% of days (1.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.1 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~4.6mm (P95)
Why this matters
Measurable rain is possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 2% of days (0.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.8 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Overcast skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat Minor
Hot days Measures: Hot days (>=30C). Observed about 1% of days (0.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~33°C (P95)
Why this matters
Hot days are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 1% of days (0.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~7.2h (P95)
Why this matters
Several rainy hours are possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
Is August a good time to visit San Francisco?
Typical August days in San Francisco reach highs of 21°C (70°F) with nights around 13°C (55°F). It usually feels mild by day and cool after dark. It is one of the drier months, which suits outdoor exploring and sightseeing.
What are temperatures like in August?
In August, you can usually expect highs of 21°C (70°F) and lows near 13°C (55°F). That means mild days and cool nights, so pack layers you can add or remove.
How much does it rain in August?
Rainfall in August averages 1 mm (0.04 in) across roughly 0 days. Overall it is a mostly dry time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in August?
You can expect about 14 hours of daylight in August. Sunrise is typically around 05:25 and sunset near 19:00. You get long days with comfortable amounts of daylight.
How strong is the sun in August?
UV levels frequently reach very high levels (around 8), so strong sun protection is essential, especially around midday.
Is it windy in August?
In August, average wind speeds are around 15 km/h (9 mph), with gusts on the windiest days reaching about 53 km/h (33 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.