Hayward, California Weather History

California, United States  •  45 yrs data 📍 37.6480°N, 122.0725°W
°F / °C
☀️

Quick Climate Facts

(1981 – 2025)
Hottest Month
🔥
Aug
Avg 76.1°F
Min 49.5°F
Max 102.7°F
Coldest Month
❄️
Dec
Avg 48°F
Min 29.1°F
Max 66.9°F
Wettest Month
🌧️
Dec
106 mm
Driest Month
🏜️
Jul
0 mm
Most Humid
💧
Jan
83%
Least Humid
🌬️
Jul
60%
Highest Ever
🌡️
114.8°F
Sep 2022
Lowest Ever
🧊
20.1°F
Dec 1990
Monthly Climate Data
Month 🌤️ High Low Avg Humid % Rain (mm) Wind (m/s) Solar (kWh/m²)

Showing average climate conditions across 45 years (1981–2025)

🌍 Weather in Hayward Across Seasons

❄️ Winter in Hayward

December is Hayward's coldest month, with average lows reaching 29.1°F.
🌡️ December to February (avg)  ·  29.8°F67.6°F

🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.

☀️ Summer in Hayward

Summer temperatures in Hayward peak in August, climbing to 102.7°F.
🌡️ July to September (avg)  ·  48.6°F102°F

🌤️ Limit midday outdoor exposure and stay hydrated — this is an intense Hot Summer.

🌧️ Rainy Season in Hayward

Hayward sees its highest rainfall in December, receiving approximately 106 mm of precipitation.
🌧️ December to February (avg)  ·  up to 106 mm

☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.

📅 Monthly Averages

🌡️ Temperature Patterns

Monthly averages · 1981–2025 climate normals · °F

🌡️ Hayward Monthly Temperature Guide

Aug is the hottest month in Hayward, with average highs reaching 102.7°F, while Dec is the coldest with lows dropping to 29.1°F.

Temperatures rise steadily from spring, peak in Aug, and gradually decline through fall into winter.

These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.

🌧️ Rainfall Distribution

Monthly rainfall · 1981–2025 seasonal trends · mm/month

💨 Humidity & Wind Speed

Monthly averages · 1981–2025

💧 Rainfall & Humidity in Hayward

Hayward receives its highest rainfall in Dec, while humidity peaks during winter months.
🌧️ Wettest: Dec — 106 mm ☀️ Driest: Jul — 0 mm

💧 Humidity peaks at 83% in Jan · annual avg 72%

🌍 Climate Summary

Avg Annual Temp:62.2°F
Avg Annual Rainfall:554 mm
Avg Humidity:72%
Data Period:1981 – 2025

Hayward Climate Overview

Hayward has a warm temperate climate with warm summers and cold winters.

Temperatures peak in Aug and drop to their lowest in Dec, while rainfall is highest during winter months.

Humidity remains moderate throughout the year, especially during winter months, creating cold and damp conditions.

📈 Yearly Trends

The warmest year in Hayward's recorded history was 2014 (avg: 65.1°F), while the coldest year was 1982 (avg: 58.5°F), based on annual average temperatures.

📊 Key Climate Trends

🌡️ Annual Temperature Trend

View Range:

Average annual high/low · Last 10 years · °F

Hayward's temperatures has remained relatively stable over the past decade. The highest recorded temperature reached 114.8°F in Sep 2022, while the lowest dropped to 20.1°F in Dec 1990.

🌧️ Annual Precipitation

View Range:

Total annual precipitation · Last 10 years · mm/year

Annual rainfall in Hayward shows noticeable variation. Rainfall varies year-to-year without a clear long-term trend.
📋 Yearly Climate Data Overview

🔥 hottest  ·  ❄️ coldest  ·  🌧️ wettest

Year Min Temp Avg Temp Max Temp Rainfall (mm) Avg Humidity Avg Wind

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❓ Frequently Asked Questions

What is the hottest month in Hayward?
Based on 45 years of data (1981–2025), Aug is typically the hottest month in Hayward, California, with average high temperatures around 102.7°F.
What is the coldest month in Hayward?
Dec is the coldest month in Hayward, with average low temperatures around 29.1°F.
What is the rainiest month in Hayward?
Dec receives the most rainfall with approximately 106 mm, while Jul is the driest with 0 mm.
What was the highest temperature ever recorded in Hayward?
The highest recorded temperature was 114.8°F in Sep 2022. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Hayward?
The lowest recorded temperature was 20.1°F in Dec 1990.
How many years of data does this page cover?
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Hayward get?
Hayward receives the most sunlight in Jun with an average solar radiation of 7.12 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in California.
Where does this weather data come from?
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.

📚 Data Source

All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.

Parameters included:
  • Temperature (Min, Max)
  • Precipitation
  • Relative Humidity
  • Wind Speed
  • Solar Radiation
Data specifications:
  • Resolution: Monthly
  • Spatial: 0.5° × 0.625°
  • Source: MERRA-2
  • Coverage: 1981–2025
  • Years: 45