San Francisco is 0.9°C (1.6°F) warmer by day, San Francisco has 1.5°C (2.7°F) warmer nights, Washington gets 489 mm (19.3 in) more rain a year.
San Francisco is at its warmest in September and coolest in January, while Washington peaks in July and bottoms out in January. Month for month, San Francisco is the warmer of the two in 7 of 12 months.
Washington is the wetter of the two, collecting 1,108 mm (43.6 in) of rain a year against 619 mm (24.4 in) in San Francisco. The most comfortable time to visit is July, August and September in San Francisco and May, June and September in Washington.
| San Francisco | Metric | Washington |
|---|---|---|
| 🌡️ Temperature | ||
| 65.8°F | 🌡️Average daytime high | 64.2°F |
| 49.1°F | 🌙Average nighttime low | 46.4°F |
| September | 🔥Hottest month | July |
| January | ❄️Coldest month | January |
| 🌧️ Rain | ||
| 24.4 in | 🌧️Annual rainfall | 43.6 in |
| December | ☔Wettest month | July |
| July | 🏜️Driest month | February |
| 💨 Climate | ||
| 77% | 💧Average humidity | 76% |
| 2.3 m/s | 💨Average wind speed | 2.7 m/s |
Overnight, San Francisco typically falls to around 9.5°C (49.1°F) while Washington settles near 8°C (46.4°F).
San Francisco is hottest in September and coldest in January, whereas Washington peaks in July and is coolest in January.
San Francisco sees the most rain in December and the least in July; Washington is wettest in July and driest in February.
San Francisco feels the more humid of the two, averaging 77% relative humidity against 76%.
For Washington, the pick of the year is May, June and September.
Month by month, here is the coldest night, the average day and the hottest afternoon each city can expect. Switch Compare to read rainfall, humidity, wind or solar instead, and Period to move between the long-term 45-year average and any single year — the shading is a quick warm-to-cool guide.
| Month | San Francisco | Washington | ||||
|---|---|---|---|---|---|---|
| Min | Avg | Max | Min | Avg | Max | |
| January | 43.3 | 49.8❄️ | 56.3 | 24.8 | 32❄️ | 39.2 |
| February | 44.6 | 51.3 | 57.9 | 26.8 | 34.9 | 43 |
| March | 46 | 52.9 | 59.9 | 33.3 | 42.6 | 52 |
| April | 47.1 | 55 | 63 | 42.8 | 52.9 | 63.1 |
| May | 49.6 | 58.3 | 66.9 | 53.2 | 62.8 | 72.1 |
| June | 52 | 61.7 | 71.2 | 63 | 72.3 | 81.5 |
| July | 53.6 | 63.3 | 73 | 68.9 | 78.3🔥 | 87.4 |
| August | 54.9 | 64.8 | 74.5 | 67.5 | 76.8 | 86.2 |
| September | 55.2 | 65.3🔥 | 75.4 | 60.4 | 70 | 79.5 |
| October | 52.9 | 62.2 | 71.6 | 48.2 | 57.9 | 67.6 |
| November | 47.7 | 55.2 | 62.8 | 37.6 | 46.4 | 55.2 |
| December | 43.5 | 50 | 56.5 | 29.5 | 36.7 | 44.1 |
| Annual Avg | 49.3 | 57.6 | 65.7 | 46.4 | 55.2 | 64.2 |
Min / mean / max temperature (°F). 🔥 marks each city's hottest month, ❄️ its coldest; shading runs cool blue to warm red.
The same figures plotted out, so the shape of a typical year is easier to see than in a grid. Where the two lines run close together San Francisco and Washington feel alike; where they separate, they are genuinely different places to be.
Hover or tap any point to read the exact figures. San Francisco Washington
See how San Francisco and Washington stack up against other cities. Swipe for more.
Choose which city to keep, then search for any other city in our database — we'll build the comparison for you.
Quick answers to the questions people ask most when comparing San Francisco and Washington — each drawn straight from the climate figures above.
San Francisco is the warmer of the two. It averages daytime highs of 18.8°C (65.8°F) against 17.9°C (64.2°F) in Washington — roughly 0.9°C (1.6°F) warmer by day. Nights are milder in San Francisco, with average lows of 9.5°C (49.1°F) versus 8°C (46.4°F).
San Francisco is hottest in September, averaging highs of about 24.1°C (75.4°F), while Washington peaks in July at around 30.8°C (87.5°F). That makes Washington the hotter of the two at the height of summer.
Washington gets colder. In its coldest month (January) overnight lows average about -4°C (24.8°F), compared with 6.3°C (43.3°F) at the low point of the year in San Francisco.
Washington is the wetter city, collecting about 1,108 mm (43.6 in) of rain a year versus 619 mm (24.4 in) in San Francisco. San Francisco is wettest in December and driest in July; Washington is wettest in July and driest in February.
Humidity is similar in both, averaging around 77% in San Francisco and 76% in Washington across the year.
The most comfortable months in San Francisco are July, August and September, when average temperatures are at their mildest.
Washington is at its most pleasant around May, June and September, based on the mildest average temperatures of the year.
San Francisco is the warmer city in 7 of the 12 months of the year. The gap is widest in January, about 9.9°C (17.8°F), and narrowest in April, about 1.2°C (2.2°F).
Washington has the bigger seasonal swing, about 25.7°C (46.3°F) between its coldest and hottest months versus 8.6°C (15.5°F) in San Francisco — so San Francisco has the steadier, more even climate.
On climate alone, San Francisco comes out ahead — it offers warmer days and less rain than Washington. Washington is the better fit only if you'd actually prefer cooler weather and more rainfall.
Every figure on this page is calculated from NASA POWER satellite climate data spanning 1981–2025 (45 years). The averages describe the long-term climate of San Francisco and Washington, not a single year's weather or a short-range forecast.
