Best time to visit San Francisco

Re-score for me — drag the dial — every chart on the page recolours live for your heat limit 27°C
I'm comfortable up to 27°C feels-like
22° heat-averse 30° heat-loving

Default 27 °C is the upper edge of the Holiday Climate Index "ideal comfort" band (Scott, Rutty, Amelung & Tang, 2016). Above this, most warm-tourism travellers report measurable discomfort.

Saved to this browser. Changes update the strips below.
Recent · 2020-2024
Interest Google Trends 2021-2025 searches, not arrivals (?)
Day · avg daily high (?)
Night · avg overnight low (?)
Heatwaves · days/yr ≥35°C ETCCDI TX35 (?)
<1
UV index · On a typical day around midday, UV is about this (?)
235688876432
On the sunniest 1 in 10 days, UV reaches this — and even higher
4789101094
PM2.5 air quality · on a typical day (?)
1414121110109910111416
On the worst 1 in 10 days, PM2.5 reaches this — and even higher
222519151413121215192731
October 9/10 feels 19°C (−1°C vs 1991-2020) · HCI 91/100
Day 21° · Night 13° ⚠ <1 days/yr ≥35° · peak 3 in worst year 62% humidity 25 km/h wind 3 rain days (29h) 224h sun
Thermal 8
Sky 10
Rain 10
Wind 9

Higher = better, including rain & wind (green = "doesn't hurt the score", not "lots of it").

How is this scored? HCI / Steadman / CCI gate — full methodology and citations below.

Compare with another destination

Add as many as you like — stacked below the main strips above. Each row is just the recent-window score strip and (for beach destinations) sea-temperature strip.

Tours in San Francisco

29 top-rated tours via Viator. Booking links earn this site a commission at no cost to you. Map locations are approximate (centred on San Francisco).

  1. 1Golden Gate Bridge Muir Woods Sausalito with Optional Alcatraz4.94★ (1,256)6hfrom $119🔥 Selling fast
  2. 2Small Group: Ultimate Napa & Sonoma Wine Tour from San Francisco4.80★ (689)9hfrom $179🔥 Selling fast
  3. 3San Francisco Bay Sailing Cruise4.87★ (639)1h 30mfrom $72🔥 Selling fast
  4. 4Vantigo - The Original San Francisco VW Bus Tour4.98★ (782)3hfrom $129🔥 Selling fast
  5. 5San Francisco Movie Sights City Tour4.92★ (1,260)3hfrom $67🔥 Selling fast
  6. 6Napa and Sonoma Wine Country Full-Day Tour from San Francisco4.33★ (4,512)from $157🔥 Selling fast
  7. 7Yosemite National Park: Full Day Tour from San Francisco4.15★ (944)14hfrom $199🔥 Selling fast
  8. 8Napa and Sonoma Wine Tour from San Francisco4.83★ (175)9hfrom $170🔥 Selling fast
  9. 9Alcatraz Tour + 90 min San Francisco City Open Air Van Tour5.00★ (9)5hfrom $131🔥 Selling fast
  10. 10San Francisco, Muir Woods, Sausalito and Optional Alcatraz Tour4.84★ (1,494)8hfrom $107
  11. 11San Francisco City Tour, Muir Woods & Sausalito: Half or Full Day4.91★ (774)from $107
  12. 12San Francisco Grand City Tour4.20★ (605)4hfrom $69🔥 Selling fast
  13. 13Private Tour to Monterey, Carmel, 17-Mile Drive, Pebble Beach5.00★ (6)11hfrom $1199🔥 Selling fast
  14. 14Muir Woods and Sausalito Tour (Return by Bus or Ferry)4.41★ (5,152)from $80🔥 Selling fast
  15. 15Muir Woods and Sausalito Morning Tour Small-Group Half Day4.56★ (590)4h 30mfrom $99🔥 Selling fast
  16. 16Monterey, Carmel and 17-Mile Drive: Full Day Tour from SF4.24★ (2,201)11hfrom $129🔥 Selling fast
  17. 172hr. INTERACTIVE Sailing Experience on San Francisco Bay4.97★ (93)2hfrom $149🔥 Selling fast
  18. 18San Francisco Fire Engine Tour4.80★ (326)1h 30mfrom $69🔥 Selling fast
  19. 19Alcatraz Plus San Francisco City Combo Tour4.59★ (44)from $158🔥 Selling fast
  20. 20Small Group Yosemite and Giant Sequoias Day Trip from San Francisco4.90★ (3,889)14hfrom $239
  21. 21San Francisco Love Tour4.85★ (2,993)2hfrom $85
  22. 22Chinatown & North Beach\Little Italy: 7 Tastings & History4.86★ (1,192)4hfrom $96
  23. 23Painted Ladies San Francisco City Tour4.91★ (2,210)2hfrom $82
  24. 24Small-Group Wine Country Tour from San Francisco with Tastings4.91★ (1,599)9h 30mfrom $179
  25. 25Skip The Bus: San Francisco By Luxury Van Tour4.95★ (856)4hfrom $129
  26. 26North Beach & Little Italy Walking Tour: Food, History & Flavor4.83★ (1,095)3hfrom $86
  27. 27Chinatown Walking Tour: Food, History & Flavor4.87★ (625)3hfrom $86
  28. 28San Francisco: The Mission District Food Tour with 5 Local Dishes4.82★ (891)3hfrom $85
  29. 29Muir Woods and Sausalito Small-Group Tour4.74★ (813)5hfrom $89

Last refreshed 2026-05-25.

Similar climatesEze82% · Montserrat81% · Napa80%

Other destinations with the most-alike year-round climate to San Francisco (apparent temperature, rain hours, sunshine — matched within the same trip-profile). The ±N chip compares each match's typical score for the current month against San Francisco's. Based on the 2020-2024 climatology, not this year's actual weather.

Month-by-month

Month Temp °C Feels °C Rain days Rain h Rain h/day Humidity Wind km/h Sun h UV Interest Score
Jan 8–14 11 10 111 11.1 77% 23 164 2 Quiet 6
Feb 8–15 11 6 79 13.2 69% 25 193 3 Quiet 7
Mar 9–14 10 10 131 13.1 71% 28 221 5 Quiet 6
Apr 10–15 12 3 37 12.3 72% 30 263 6 Quiet 8
May 11–17 14 3 30 10.0 67% 32 298 8 Quiet 8
Jun 13–19 15 0 7 — 67% 33 296 8 Quiet 8
Jul 13–19 16 0 2 — 71% 30 297 8 Quiet 8
Aug 14–20 18 0 3 — 71% 30 283 7 Peak 9
Sep 14–20 19 1 12 12.0 70% 27 254 6 Busy 9
Oct 13–21 19 3 29 9.7 62% 25 224 4 Moderate 9
Nov 10–16 14 6 65 10.8 66% 21 190 3 Peak 8
Dec 8–14 11 12 150 12.5 77% 21 149 2 Busy 6

UV Index in San Francisco by Month

UV index in San Francisco peaks at 8 (very high) in June, dropping to 2 (low) in December. June, July reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.

Best months in detail

October

9/10

13–21°C (feels 19°C) · 3 rain days (29h) · 224 sun hours · 62% humidity · Moderate crowd · UV 4 (moderate)

September

9/10

14–20°C (feels 19°C) · 1 rain days (12h) · 254 sun hours · 70% humidity · Busy crowd · UV 6 (high)

August

9/10

14–20°C (feels 18°C) · 0 rain days (3h) · 283 sun hours · 71% humidity · Peak crowd · UV 7 (high) · sunniest 1 in 10 days reach 9 (very high)

Every month

Show the other 9 months in detail

January

6/10

8–14°C (feels 11°C) · 10 rain days (111h) · 164 sun hours · 77% humidity · Quiet crowd · UV 2 (low)

February

7/10

8–15°C (feels 11°C) · 6 rain days (79h) · 193 sun hours · 69% humidity · Quiet crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)

March

6/10

9–14°C (feels 10°C) · 10 rain days (131h) · 221 sun hours · 71% humidity · Quiet crowd · UV 5 (moderate) · sunniest 1 in 10 days reach 7 (high)

April

8/10

10–15°C (feels 12°C) · 3 rain days (37h) · 263 sun hours · 72% humidity · Quiet crowd · UV 6 (high) · sunniest 1 in 10 days reach 8 (high)

May

8/10

11–17°C (feels 14°C) · 3 rain days (30h) · 298 sun hours · 67% humidity · Quiet crowd · UV 8 (high) · sunniest 1 in 10 days reach 9 (very high)

June

8/10

13–19°C (feels 15°C) · 0 rain days (7h) · 296 sun hours · 67% humidity · Quiet crowd · UV 8 (very high) · sunniest 1 in 10 days reach 10 (very high)

July

8/10

13–19°C (feels 16°C) · 0 rain days (2h) · 297 sun hours · 71% humidity · Quiet crowd · UV 8 (very high) · sunniest 1 in 10 days reach 10 (very high)

November

8/10

10–16°C (feels 14°C) · 6 rain days (65h) · 190 sun hours · 66% humidity · Peak crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)

December

6/10

8–14°C (feels 11°C) · 12 rain days (150h) · 149 sun hours · 77% humidity · Busy crowd · UV 2 (low)

Comparisons people search for

Pairs validated by Google Autocomplete demand — only pairs people actually compare.

Frequently asked questions about visiting San Francisco

When is the best time to visit San Francisco?

October is the highest-scoring month (9/10 on the Holiday Climate Index). Typical conditions: 13–21°C (3 rainy days). The top three months by score are October, September, August.

What is the worst time to visit San Francisco?

December is the lowest-scoring month (6/10). Typical conditions: 8–14°C (12 rainy days).

When are crowds lowest in San Francisco?

Search-interest seasonality (Google Trends 2021-2025) is lowest in February and peaks in August. Interest tracks both in-trip visitors and lead-time planners, so treat it as a "destination is on people's minds" signal rather than literal arrivals.

Which months in San Francisco have good weather but fewer tourists?

October (climate 9/10, crowd index 47) and April (climate 8/10, crowd index 1) — shoulder months with above-average climate and below-median search-interest. Often the best value-for-weather trade.

What is the UV index in San Francisco by month?

UV peaks at 8 (very high) in June and is lowest in December at 2 (low). Monthly peak values: Jan 2, Feb 3, Mar 5, Apr 6, May 8, Jun 8, Jul 8, Aug 7, Sep 6, Oct 4, Nov 3, Dec 2. June, July reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.

What is the UV index in San Francisco in June?

June is the peak UV month in San Francisco, with a daily-peak UV index of 8 (very high). At this level, sunburn can occur in under 20 minutes on unprotected fair skin. Apply SPF 50+, wear protective clothing and a hat, and avoid direct midday sun (11:00–17:00).

How high can UV get in San Francisco on the sunniest days?

Most days look like the monthly average, but on the sunniest ~1 in 10 days UV climbs higher than the mean suggests. June is the worst case: typical days average UV 8 (very high), but the top 10% of days reach UV 10 (very high) — and even higher. Months where the sunniest days routinely exceed the typical reading: February, March, April, May, June, July, August, November. Plan sun protection for the worst case, not the average.

Is air quality in San Francisco bad for travelers?

PM2.5 (fine-particle pollution) exceeds the WHO sensitive-group guideline (15 µg/m³) in 7 months: January, February, March, September, October, November, December. The worst month is December with a typical-day mean of 16 µg/m³ (unhealthy for sensitive); on the worst 10% of days PM2.5 reaches 31 µg/m³ (unhealthy) and higher. People with asthma, heart conditions, or sensitive children may want to avoid these months or limit outdoor activity. Source: CAMS via Open-Meteo.