May Weather in Vacaville, United States

Last updated: June 24, 2025

In Vacaville, United States, the average temperature in May hovers around 19°C (66°F). Expect a minimum of 5°C (41°F) and a possible maximum of 38°C (100°F). With an average humidity of 74%, you might feel that warmth a little more intensely. Additionally, anticipate 17 mm (0.7 in) of precipitation over about 2 days during the month. Stay prepared for a mix of sunny and rainy moments!

May Temperature in Vacaville

In May in Vacaville, the average temperature is 19°C (66°F). Maximum temperatures can reach 38°C (100°F), while minimums can drop as low as 5°C (41°F). It's advisable to pack layers and be prepared for both warm days and cool evenings while traveling.

May Weather in Vacaville: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Vacaville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Vacaville, May typically has an average temperature of 19°C (66°F), with highs reaching up to 38°C (100°F) and lows dropping to around 5°C (41°F).

Data source: Temperature data for Vacaville generated using information from the Copernicus Climate Change Service.

May Precipitation in Vacaville

In Vacaville in May, the precipitation amount is 17 mm (0.7 in) over a span of 2 days.

May Precipitation Trends in Vacaville

The chart displays monthly precipitation patterns in Vacaville, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Vacaville, May typically receives around 17 mm (0.7 inches) of precipitation spread over approximately 2 days.

Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

May Humidity in Vacaville

In Vacaville in May humidity is 74%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it ideal for leisurely outdoor exploration but potentially heavy for those not accustomed to tropical conditions.

May Average Humidity in Vacaville

This chart illustrates the average monthly humidity levels in Vacaville, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Vacaville is approximately 74%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Vacaville

In Vacaville in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Vacaville.

Maximum UV Index Levels in Vacaville for May

The chart shows the monthly maximum UV Index (UVI) for Vacaville in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Vacaville typically reaches 10, which falls under the very high exposure category.

Data source: Vacaville May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How May Weather in Vacaville Compares to Other Months

Weather in Vacaville varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Vacaville, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Vacaville, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	10°C (50°F)	119 mm (4.7 inches)	84%	moderate
February Weather	12°C (53°F)	102 mm (4.0 inches)	84%	moderate
March Weather	13°C (56°F)	77 mm (3.0 inches)	83%	high
April Weather	16°C (61°F)	32 mm (1.3 inches)	81%	very high
May Weather	19°C (66°F)	17 mm (0.7 inches)	74%	very high
June Weather	22°C (71°F)	1 mm (0.1 inches)	64%	extreme
July Weather	22°C (71°F)	0 mm (0.0 inches)	44%	extreme
August Weather	22°C (72°F)	0 mm (0.0 inches)	36%	very high
September Weather	21°C (71°F)	1 mm (0.0 inches)	44%	very high
October Weather	18°C (65°F)	26 mm (1.0 inches)	65%	high
November Weather	13°C (56°F)	38 mm (1.5 inches)	84%	moderate
December Weather	10°C (50°F)	85 mm (3.3 inches)	83%	moderate