Live Weather & Forecast
Weather in Port Costa
California, United States · Real-time conditions & 3-day outlook
11°C
Feels like 12°C
52°F / Feels 53°F
Partly cloudy
Port Costa, California
🌙 Nighttime
Updated: 2026-04-13 00:15
Humidity
89%
Wind
3.6 km/h W
Wind Gust
4.4 km/h
Pressure
1017 mb
Visibility
16 km
UV Index
0
(Low)
Precipitation
0 mm
Cloud Cover
75%
Dew Point
7°C
Wind Degree
261°
Air Quality Index
US EPA: Good
UK DEFRA: Low (2)
CO
203.9 μg/m³
NO₂
17.5 μg/m³
O₃
24 μg/m³
SO₂
3 μg/m³
PM 2.5
15 μg/m³
PM 10
17.5 μg/m³
Today's Hourly Forecast
24-hour breakdown for Port Costa, California
12 AM
10°
Clear
1 AM
11°
Partly cloudy
2 AM
9°
Clear
3 AM
9°
Clear
4 AM
8°
Clear
5 AM
8°
Clear
6 AM
8°
Clear
7 AM
9°
Sunny
8 AM
10°
Sunny
9 AM
11°
Sunny
10 AM
11°
Sunny
11 AM
13°
Partly Cloudy
12 PM
15°
Sunny
1 PM
16°
Sunny
2 PM
17°
Sunny
3 PM
17°
Partly Cloudy
4 PM
18°
Partly Cloudy
5 PM
17°
Sunny
6 PM
17°
Sunny
7 PM
15°
Sunny
8 PM
13°
Clear
9 PM
12°
Clear
10 PM
11°
Clear
11 PM
10°
Clear
3-Day Forecast
Daily overview for Port Costa, California
Today
Sunny
18°
/
8°
🌧️ 0% chance of rain
💧 Avg. humidity: 76%
💨 Max wind: 16.6 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.3
🌅 Sunrise: 06:36 AM
🌇 Sunset: 07:44 PM
🌙 Waning Crescent
🌑 Moon: 23% lit
Tue, Apr 14
Mist
16°
/
7°
🌧️ 0% chance of rain
💧 Avg. humidity: 82%
💨 Max wind: 14 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.6
🌅 Sunrise: 06:34 AM
🌇 Sunset: 07:45 PM
🌙 Waning Crescent
🌑 Moon: 15% lit
Wed, Apr 15
Cloudy
16°
/
7°
🌧️ 0% chance of rain
💧 Avg. humidity: 80%
💨 Max wind: 21.6 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.5
🌅 Sunrise: 06:33 AM
🌇 Sunset: 07:46 PM
🌙 Waning Crescent
🌑 Moon: 8% lit
Best Time to Visit Port Costa
Plan your trip to Port Costa, United States around the most favorable weather conditions.
Peak Season
June – September
Warm, dry summers — ideal for outdoor activities.
Shoulder Season
April – May, October
Fewer crowds, moderate prices, mild weather.
Off Season
November – March
Cooler temperatures; some regions may experience rain or snow.
Frequently Asked Questions
What is the current weather in Port Costa?
Current conditions in Port Costa: Partly cloudy, temperature 11°C, humidity 89%.
What is the best time to visit Port Costa?
The best time to visit Port Costa is typically June – September. Warm, dry summers — ideal for outdoor activities.
What is the climate like in Port Costa?
Port Costa is located at approximately 38° latitude. It has a temperate climate with warm summers and cold winters.
Does it rain a lot in Port Costa?
The wettest period in Port Costa is typically during November – March. Cooler temperatures; some regions may experience rain or snow.
What should I pack for a trip to Port Costa?
For visits to Port Costa during June – September: light clothing and sun protection. For November – March: layers and a waterproof jacket are recommended.
What country is Port Costa in?
Port Costa is located in United States, in the state of California.
What are the public holidays in Port Costa in 2026?
View the 2026 public holidays for Port Costa on our Holidays page.
What are the GPS coordinates used for the weather forecast in Port Costa?
The weather forecast for Port Costa uses coordinates 38.0448, -122.1844.