Gilroy, California Weather History

California, United States  •  45 yrs data 📍 37.0146°N, 121.5572°W
°F / °C
☀️

Quick Climate Facts

(1981 – 2025)
Hottest Month
🔥
Jul
Avg 78.8°F
Min 50.3°F
Max 107.3°F
Coldest Month
❄️
Dec
Avg 49°F
Min 29.4°F
Max 68.7°F
Wettest Month
🌧️
Jan
95 mm
Driest Month
🏜️
Jul
1 mm
Most Humid
💧
Feb
79%
Least Humid
🌬️
Jul
44%
Highest Ever
🌡️
115.6°F
Sep 2022
Lowest Ever
🧊
20.3°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 Gilroy Across Seasons

❄️ Winter in Gilroy

December is Gilroy's coldest month, with average lows reaching 29.5°F.
🌡️ December to February (avg)  ·  30.4°F69.4°F

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

☀️ Summer in Gilroy

Summer temperatures in Gilroy peak in July, climbing to 107.2°F.
🌡️ July to September (avg)  ·  50.4°F105.8°F

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

🌧️ Rainy Season in Gilroy

Gilroy sees its highest rainfall in January, receiving approximately 95 mm of precipitation.
🌧️ December to February (avg)  ·  up to 95 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

🌡️ Gilroy Monthly Temperature Guide

Jul is the hottest month in Gilroy, with average highs reaching 107.3°F, while Dec is the coldest with lows dropping to 29.4°F.

Temperatures rise steadily from spring, peak in Jul, 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 Gilroy

Gilroy receives its highest rainfall in Jan, while humidity peaks during winter months.
🌧️ Wettest: Jan — 95 mm ☀️ Driest: Jul — 1 mm

💧 Humidity peaks at 79% in Feb · annual avg 63%

🌍 Climate Summary

Avg Annual Temp:64°F
Avg Annual Rainfall:486 mm
Avg Humidity:63%
Data Period:1981 – 2025

Gilroy Climate Overview

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

Temperatures peak in Jul 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 dry conditions.

📈 Yearly Trends

The warmest year in Gilroy's recorded history was 2014 (avg: 67.1°F), while the coldest year was 1982 (avg: 60.4°F), based on annual average temperatures.

📊 Key Climate Trends

🌡️ Annual Temperature Trend

View Range:

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

Gilroy's temperatures has remained relatively stable over the past decade. The highest recorded temperature reached 115.6°F in Sep 2022, while the lowest dropped to 20.3°F in Dec 1990.

🌧️ Annual Precipitation

View Range:

Total annual precipitation · Last 10 years · mm/year

Annual rainfall in Gilroy 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 Gilroy?
Based on 45 years of data (1981–2025), Jul is typically the hottest month in Gilroy, California, with average high temperatures around 107.3°F.
What is the coldest month in Gilroy?
Dec is the coldest month in Gilroy, with average low temperatures around 29.4°F.
What is the rainiest month in Gilroy?
Jan receives the most rainfall with approximately 95 mm, while Jul is the driest with 1 mm.
What was the highest temperature ever recorded in Gilroy?
The highest recorded temperature was 115.6°F in Sep 2022. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Gilroy?
The lowest recorded temperature was 20.3°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 Gilroy get?
Gilroy receives the most sunlight in Jun with an average solar radiation of 8.14 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