Palo Alto weather in October

October is the month when Palo Alto locals stop envying anyone. Afternoons are still warm, usually in the 70s. Nights turn crisp. The air is often the clearest since spring. The first storm of the season may arrive near the end of the month to settle the dust. The flip side is fire weather: dry offshore winds and wildfire smoke are both part of the October picture in some years.

The averages on this page are NOAA's 1991 to 2020 climate normals for the Palo Alto station (USC00046646), on the flats at about 25 feet. NOAA classifies the station's numbers as "representative" because of gaps in its record, so treat tenths of a degree as approximate. Sun times are calculated for central Palo Alto for October 2027 and match published tables within a minute. Nothing here is a forecast. Our weather guide has the full year.

October by the numbers

The ocean row is NOAA's long term average for its buoy about 18 nautical miles west of San Francisco. NOAA does not publish one for Half Moon Bay.

Warm days, cooling nights

October's average high of 74.0°F is about five and a half degrees below September. The average low of 48.4°F is more than four degrees cooler. The Palo Alto station averages 6.8 days at 80°F or hotter in October. Only about 0.3 days reach 90°F, but early October heat spells do happen. In early October 2026 the National Weather Service issued a heat advisory for the Bay Area, with the city warning of highs from the upper 80s to the low 100s.

The daily range stays wide, about 25 degrees on average. Expect sweater mornings and T-shirt afternoons, then a quick chill after sunset.

Rain: the season turns

October averages 0.64 inches, but rain is lumpy this early. The median is only 0.32 inches. In one October out of four the station records less than a tenth of an inch. In one out of four it gets more than 0.96 inches. About 2.5 days bring measurable rain.

When October rain comes, it can come all at once. On October 24, 2021, a powerful atmospheric river dropped several inches of rain across the Bay Area in about a day, flooding streets and ending a long dry spell overnight. More often the first storm is a modest front that wets the pavement, brings out the smell of rain on dry ground and starts the hills on their way back to green by November.

The first rain after a long dry summer makes roads slick with oil and fallen leaves. Drive carefully on that first wet morning.

Daylight

October days shorten steadily. Sunrise moves from about 7:04 a.m. on October 1 to about 7:32 a.m. on October 31, the latest sunrises of the year because daylight saving time is still in effect. Sunset moves from about 6:52 p.m. to about 6:12 p.m. Daylight drops from about 11 hours 48 minutes to 10 hours 39 minutes.

Clocks fall back on the first Sunday of November, which is November 7 in 2027. Until then, early morning runners start in the dark. Stanford posts October hours of 6:30 a.m. to 6 p.m. for the Dish.

Offshore winds, smoke and air quality

Offshore winds and fire weather

Fall is the season of offshore winds. When high pressure builds over the Great Basin, dry air flows downslope toward the coast, warming and drying as it descends. Humidity can drop into the teens and gusts can be strong on the ridges. Combined with grass and brush at their driest after a rainless summer, that sets up the most dangerous fire weather of the year. The National Weather Service issues Red Flag Warnings on those days. Our emergency preparedness guide covers wildfire readiness, alerts and evacuation zones.

Smoke

October falls in the main smoke season. In October 2017, the wine country fires in Sonoma and Napa sent thick smoke across the Bay Area for more than a week. Some Octobers have no smoke at all. On hazy days, check the AirNow Fire and Smoke Map and our air quality guide.

Fog

October is one of the least foggy months for both the coast and Palo Alto. The marine layer is thin or absent much of the time. Late in the month, after the first rain, the first shallow valley fog of the season can appear over the bay flats on a calm morning.

Microclimates in October

The bay's influence evens out in October. Moffett Field, on the shoreline, averages a high of 74.1°F, essentially the same as the Palo Alto station's 74.0°F, but its average low of 53.1°F is nearly five degrees warmer. As nights lengthen, cold air drains off the hills and pools on the flats. The Palo Alto station feels that more than the bay edge.

During offshore wind events the pattern can flip. The foothills and Skyline Boulevard stay warm, windy and dry through the night while the flats cool. Ridge preserves may close areas on Red Flag days. Stanford can restrict access to the Dish during Red Flag Warnings, heat and poor air quality, so check its site before you go.

On ordinary October days, Stanford and the foothills are perfect for walking. Morning shade under the oaks is cool and the open grassland is warm by midday.

How October compares with San Francisco and San Jose

October is San Francisco's second warmest month, with downtown averaging 69.8°F. Palo Alto averages 74.0°F, so the gap shrinks to about four degrees. San Jose averages 75.8°F. Nights are warmest in San Francisco at 54.4°F and coolest in Palo Alto at 48.4°F.

Rain arrives a little sooner in the city. San Francisco averages 0.94 inches in October, against 0.64 in Palo Alto and 0.53 in San Jose. For a weekend in the city, October is about as good as it gets. If you want a guide, you can browse Bay Area tours.

The coast in October

The ocean stays near its warmest. NOAA's buoy west of San Francisco averages 57.4°F in October and the Monterey buoy 58.7°F. NOAA has no long term Half Moon Bay figure, but October often brings the coast its clearest and calmest days. Inside the bay, the Redwood City reading cools to 66.2°F.

Fall swells begin to build late in the month. October is pumpkin season on the coast. The farm stands along Highway 1 near Half Moon Bay are busy on weekends. Our pumpkin patches guide lists them.

What to pack for October

• Light layers. Short sleeves for the afternoon and a sweater for mornings near 50°F.
• A light rain jacket late in the month, just in case.
• Sun protection for clear, warm days.
• An N95 mask if smoke affects you.
• Closed shoes with grip for dusty or newly wet trails.

What October weather is good for

October suits nearly any plan outdoors. Our October trip guide covers events and dates. Weather-driven ideas:

1. Long hikes in comfortable temperatures. Our hiking guide has routes for every level.
2. Early fall color. A few street trees start turning at the end of October. Our fall colors guide tracks the season.
3. Coast and pumpkin days. Clear weather and farm stands make a good pairing.
4. Evening patios. Warm afternoons carry into comfortable early evenings.

Keep an eye on Red Flag Warnings and the AQI. Save the hike for a calm day if the wind is up.

Frequently asked questions