Weather in San Francisco tonight: Cloudy, 66°F high, low 52°F

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• 🔥 Quick Facts
• Understanding San Francisco’s Late-May Weather Pattern
• What Tonight’s Forecast Means for Your Plans
• May 2026 Temperature Trends in Statistical Context
• Spring Weather Context: Why May Matters
• How Tonight’s Weather Fits Broader 2026 Spring Trends
• Will Tonight’s Forecast Extend into the Weekend?
  • What Weather Patterns Can You Expect in San Francisco Long-Term?
  • Sources

San Francisco weather tonight shows typical late-May conditions with cloudy skies, a 66°F high, and 52°F overnight low. The moderate temperatures reflect San Francisco’s spring climate pattern, as the city heads into the early part of late May. This forecast aligns with historical May averages—highs range from 60°F to 71°F with lows between 51°F and 56°F across the month, according to AccuWeather data for May 2026. Tonight’s conditions are favorable for evening outdoor activities across the Bay Area.

Understanding San Francisco’s Late-May Weather Pattern

Late May typically marks the transition point in San Francisco’s spring season, where afternoon warmth gives way to cooler, cloudier evenings. The 66°F high forecast for tonight sits near the middle of May’s typical temperature range. This consistency reflects the city’s marine climate, where the Pacific Ocean’s moderating influence prevents extreme temperature swings even as summer approaches. Historical records show that May is 3°F warmer on average than April in San Francisco, signaling the seasonal shift toward warmer weather, though summer fog patterns haven’t fully intensified yet.

The cloudy evening forecast aligns with regional patterns observed across the Bay Area. According to the National Weather Service, mostly cloudy conditions are expected after sunset, with winds from the southwest at 10-20 mph. This wind pattern is typical for May, as it represents the increased onshore flow characteristic of late spring. Unlike June, when San Francisco’s famous fog can dominate evening and morning hours, May cloudiness is generally thinner and less persistent.

What Tonight’s Forecast Means for Your Plans

The 52°F overnight low is comfortable for evening activities that don’t require heavy layers. Current conditions suggest that attending outdoor events—such as the Ferry Flicks screenings at Fort Point Beer Garden scheduled through evening hours—will be pleasant with light jackets recommended. The streaming entertainment options also remain strong for those preferring indoor alternatives, with Apple TV releasing new content regularly for users seeking entertainment under cloudy skies.

Wind speeds of 10-20 mph from the southwest will create gusty conditions on exposed areas like waterfront locations or hilltops. For those planning evening walks or outdoor dining, positions sheltered from westerly winds will feel warmer. The sunset time of approximately 8:20 PM provides a long window for twilight activities before temperatures drop toward the 52°F low.

May 2026 Temperature Trends in Statistical Context

Weather Metric	Tonight (May 22)	May Monthly Average
Daytime High	66°F	64-67°F
Nighttime Low	52°F	53-54°F
Conditions	Cloudy evening	Mixed cloud/sun
Wind Speed	SW 10-20 mph	5-15 mph average
Typical Precipitation	None expected	0.3 inches for month

Tonight’s conditions are representative of late May in San Francisco. The 66°F high is typical for this period, while the cloudy evening forecast reflects regional moisture patterns as the Pacific high-pressure system approaches. May typically sees below-normal precipitation compared to spring months, with the month averaging approximately 0.3 inches of rain. The 2026 Farmers Almanac forecast indicates above-normal temperatures and below-normal rainfall for the Pacific Southwest through spring, which aligns with the current pattern.

Spring Weather Context: Why May Matters

“In the month of May, San Francisco is mild and dry, making this a great time of year to explore the city’s many cultural sights. As summer gets closer, you can expect more sun and less cloud cover in the city.”

— Travel and Climate Analysis, Thomas Cook Weather Guide

May represents a pivotal month in San Francisco’s seasonal weather cycle. The 66°F high tonight sits at the warmer end of mid-spring conditions, signaling the city’s gradual transition toward summer. Unlike June—which focuses on atmospheric moisture and fog development—May emphasizes the shift from spring’s unpredictable patterns to the drier, sunnier conditions typical of summer arrival. Wind patterns during May have already shifted toward the southwest, which enhances the classical San Francisco evening cooldown. This southwesterly flow brings slightly warmer air during afternoons but also enables the marine layer to intrude during evenings, producing tonight’s cloudy forecast.

The 52°F overnight low aligns with seasonal norms, as the marine influence strengthens after sunset. Unlike inland areas that may dip into the 40s, the Bay’s water temperature—still cool at around 55-60°F—moderates San Francisco’s extremes. This maritime moderation is a defining characteristic of the city’s May weather, preventing dramatic temperature swings while maintaining the mild conditions that make the month ideal for visitors and locals alike.

How Tonight’s Weather Fits Broader 2026 Spring Trends

The 66°F to 52°F range tonight reflects broader 2026 spring patterns observed across coastal California. Earlier in spring 2026, meteorologists noted the transition from La Niña to neutral Pacific conditions, which influences atmospheric circulation patterns. May 2026’s forecast of above-normal temperatures with below-normal rainfall is consistent with this shift toward warmer, drier conditions. The southwest wind pattern at 10-20 mph is stronger than the historical 5-15 mph May average, suggesting slightly more vigorous onshore flow this year.

This weather context is relevant for anyone planning extended outdoor activities tonight. The mild 66°F high combined with persistent clouds creates ideal conditions for evening exploration without excessive heat or rain concerns. The FoodieLand Night Market, running through May 24, benefits from these stable weather patterns across the Bay Area, with broadcasting of evening entertainment events assured by the clear-to-cloudy, dry forecast.

Will Tonight’s Forecast Extend into the Weekend?

The cloudy conditions and 52°F low tonight are expected to transition as we move into the weekend. National Weather Service forecasts suggest gradual clearing Friday evening into Saturday morning, with highs potentially reaching 62-65°F Saturday. The southwest wind will remain moderate through the period, but intensity is expected to ease slightly. This improving trend supports the broader spring forecast, where May typically transitions toward sunnier, warmer conditions by month’s end. Looking ahead, the transition to June will bring more fog and cooler mornings, but this final week of May maintains spring’s characteristic mild, relatively stable pattern.

What Weather Patterns Can You Expect in San Francisco Long-Term?

As May progresses toward June, San Francisco residents and visitors should expect warming trends and fewer cloudy evenings, though marine influence will always present—the city’s iconic fog is most prevalent in June due to the strengthening California Current. The 66°F high tonight is characteristic of May’s transitional nature: warm enough to enjoy outdoor activities without heavy layers, yet cool enough at night (52°F) to prevent overheating during evening hours. The southwest wind pattern will remain a constant feature through spring closing, typically moderating to 10-15 mph by early June. Understanding these patterns helps explain why May is considered peak season for visiting San Francisco—the weather offers balance, with mild days, cool nights, and relatively low precipitation compared to spring’s earlier variability.

Sources

• AccuWeather — May 2026 historical temperature data and tonight’s specific forecast
• National Weather Service — San Francisco Bay Area forecasts and wind pattern analysis
• 2026 Farmers Almanac — Long-range spring outlook and precipitation trends
• Weather.gov — Official evening forecast conditions and timing
• World-Weather.info — Detailed hourly temperature records for verification