Hillsborough, CA — Weather Guide

In Hillsborough, the weather ranges from cool 57°F highs in winter to a warm 70°F in early fall, creating a year-round outdoor lifestyle that boosts property appeal, especially for families and professionals. The area features notable microclimates—some pockets near the Bay get cooler foggy mornings while others inland bask in more sun, so your choice of neighborhood literally means choosing your weather. Surprisingly, despite its proximity to the coast, Hillsborough experiences less fog than nearby San Francisco, making it a sun-soaked haven for buyers craving clear skies.

64°FAvg High
20.9 inAnnual Rain
245Sunny Days/Year
5 distinct zonesMicroclimates

Fun facts

Sunny Side Bay

Less fog than SF

Hillsborough experiences fewer foggy mornings than San Francisco, earning it the nickname 'The Sunny Side of the Bay' among locals, which enhances outdoor living appeal.

Micro Temp Swings

15°F swing

Temperature swings of up to 15°F can occur within a mile due to microclimates, influencing energy costs and garden choices significantly.

Sunset Social Buzz

Golden Hour

Local social media buzz often highlights the 'Golden Hour' sunsets in Hillsborough's elevated areas, driving demand for west-facing homes.

Season Flip

Warmer autumn

Despite common beliefs, autumn is often warmer than spring in Hillsborough, challenging typical seasonal expectations and affecting market timing.

Month-by-month guide

Jan 57° / 46° Good Crisp & cozy January's rainy season means fewer buyers braving the market — ideal for less competition in Hillsborough's luxury homes.
Feb 60° / 48° Good Misty mornings February still has rain but sunnier days — a perfect time to explore Hillsborough's estate gardens in person.
Mar 62° / 49° Good Bloom & bright March’s mild weather and blooming gardens in Hillsborough make for pleasant home tours.
Apr 63° / 50° Great Spring sparkle April’s spring sun and lower rain encourage open houses and outdoor staging in Hillsborough’s leafy streets.
May 64° / 51° Great Golden blooms May's near-dry weather means perfect conditions for inspecting outdoor features like pools and gardens.
Jun 66° / 53° Busy Sunny & social June heats up with sunny days—expect more buyer competition in this prime early summer market.
Jul 66° / 54° Busy Bright & balmy July’s dry heat and clear skies keep the Hillsborough market bustling — be ready for fast offers.
Aug 68° / 55° Busy Poolside luxe August’s warm days and almost no rain make it prime time for poolside showings and evening garden parties.
Sep 70° / 55° Good Indian summer September’s Indian summer vibe offers great weather for finalizing deals before the market cools.
Oct 69° / 54° Good Wind & wow October’s crisp air and fall colors in Hillsborough are perfect for showcasing mature landscaping.
Nov 62° / 50° Good Cozy & calm November’s rainy days slow the market, giving buyers a chance to negotiate on luxury estates.
Dec 57° / 46° Good Holiday hush December’s quiet market and festive charm in Hillsborough make it a good time to scout for deals.

Neighborhood microclimates

+3°F warmer

Hillsborough Highlands

66°F avg

Fog

The Hillsborough Highlands enjoy a slightly elevated position giving them sunnier, warmer days than the rest of the county. Residents love their large estates with sweeping views and easy access to the Hillsborough Country Club.

2°F cooler

Downtown Hillsborough

59°F avg

Fog

Downtown Hillsborough is known for its tree-lined streets and charming, older mansions. Being lower in elevation, it experiences cooler mornings often dipped in light fog that burns off by midday.

+1°F warmer

Miramar

64°F avg

Fog

The Miramar neighborhood, nestled near the Crystal Springs Reservoir, is shielded by local hills from the strong bay winds. It stays mild and comfortable year-round, perfect for those who want a balance of sun and breeze.

3°F cooler

Broadmoor

58°F avg

Fog

Broadmoor lies closer to the San Francisco Bay and is more exposed to the chilly winds that funnel through the area. Locals often call it the "Wind Corridor" for its steady breezes that keep the air fresh but cool.

2°F cooler

San Mateo

60°F avg

Fog

The nearby town of San Mateo, just south of Hillsborough, has a climate influenced by the San Francisco Bay with frequent morning fog and occasional drizzle, earning its reputation as "Fog City South."

+2°F warmer

Burlingame Hills

65°F avg

Fog

The affluent area of Burlingame Hills lies just north and enjoys a sunnier, less foggy climate than the bay-adjacent neighborhoods. It's a favorite for those who want a classic California warm-weather vibe with less chill.

What to wear in Hillsborough

The Layer Master

Bring a light sweater or blazer for open houses since spring mornings can be foggy and cool, especially downtown. Afternoons warm up nicely, perfect for exploring yards and gardens.

Spring

Sun & Breeze Ready

Expect sunny and warm days but pack a windbreaker for the breezy spots like Broadmoor and Miramar. Don’t forget sunscreen and sunglasses — those California rays are strong!

Summer

The Wind Whisperer

October can bring high winds, so secure hats and loose clothing. A stylish windbreaker is your best friend for open houses, especially near Broadmoor’s Wind Corridor.

Fall

Wet Weather Warrior

Rain is more frequent, so waterproof shoes and a sturdy umbrella are must-haves. Keep a warm jacket handy, especially in foggier neighborhoods like Downtown Hillsborough and San Mateo.

Winter

The bottom line for buyers

Spring Shopping Advantage

Aim to buy in late spring when the weather is clear and homes are at their freshest after winter rains, giving you a true feel for outdoor spaces without summer crowds.

Sunny Hills Investment

Invest in neighborhoods like the northern Hillsborough hills, where sunnier microclimates and better views consistently yield higher appreciation rates.

Rate Before Weather

Remember, interest rates fluctuate more than weather—secure your mortgage rate first, then pick your ideal microclimate to avoid missing out.

Time Your Tour

Visit Hillsborough neighborhoods at different times—from foggy early mornings to bright afternoons—to fully grasp how microclimates affect daily living and curb appeal.

Seller calendar

April — list

Spring showers taper off, making outdoor curb appeal pop in Hillsborough's lush neighborhoods.

June — photograph

Sunny, clear skies highlight pools and gardens at their best in early summer.

October — stage

Cooler temps and fall foliage create inviting interior and exterior scenes for buyers.

May — list

Near-dry weather means listings show well with minimal weather disruptions in Hillsborough.

Home maintenance

Spring

Inspect and clean gutters to handle April's and May's spring showers and prevent water damage.

Spring rains increase in April and May, with 1.5 to 0.7 inches of precipitation.

Check irrigation systems and adjust for decreasing rainfall to keep gardens thriving without overwatering.

Rain drops off sharply after March, requiring irrigation adjustments.

Summer

Prepare fire safety measures around the home, including clearing dry brush and maintaining defensible space.

Dry summer with virtually no rain from June through August increases wildfire risk.

Service air conditioning units for comfort during warm but moderate summer highs in the upper 60s to low 70s.

Summer highs reach up to 68°F with very sunny days, making cooling systems important.

Fall

Inspect roofing and seals before the return of heavier rains in November and December.

Rain increases to 3 inches or more in Nov and Dec, threatening roof integrity.

Trim trees and shrubs before high wind season to avoid damage and power outages.

High Wind Warnings are common in October, requiring proactive yard maintenance.

Winter

Check heating systems and insulate pipes to handle cooler temperatures in the mid-40s to low 50s.

Winter lows drop to mid-40s, necessitating proper heating and insulation.

Monitor for any drainage issues during the wettest months (Jan, Feb, Dec) to prevent basement or foundation problems.

Winter months see the highest rainfall, up to 4.5 inches in January.

Expert contributors

Explore nearby

Hillsborough Highlands weather & microclimate 66°F avg
Downtown Hillsborough weather & microclimate 59°F avg
Miramar weather & microclimate 64°F avg
Broadmoor weather & microclimate 58°F avg
San Mateo weather & microclimate 60°F avg
Burlingame Hills weather & microclimate 65°F avg
Hillsborough, CA — Weather Guide | Catchouse