May Weather in Umatilla, United States

Last updated: June 24, 2025

In Umatilla, United States, the average temperature in May hovers around 25°C (77°F). However, be prepared for a range, as the minimum can dip to 11°C (52°F) while highs soar to 36°C (97°F). With 97 mm (3.8 in) of precipitation spread across 9 days, the atmosphere maintains an average humidity of 68%.

May Temperature in Umatilla

In May in Umatilla, the average temperature is 25°C (77°F). Maximum temperatures can reach 36°C (97°F), while minimums can drop to as low as 11°C (52°F). This range makes it an ideal time for travelers to enjoy both warm days and cooler evenings.

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

The chart illustrates May temperature patterns in Umatilla, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Umatilla, May typically has an average temperature of 25°C (77°F), with highs reaching up to 36°C (97°F) and lows dropping to around 11°C (52°F).

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

May Precipitation in Umatilla

In Umatilla in May, the total precipitation amount reaches 97 mm (3.8 in) over the course of 9 days.

May Precipitation Trends in Umatilla

The chart displays monthly precipitation patterns in Umatilla, 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 Umatilla, May typically receives around 97 mm (3.8 inches) of precipitation spread over approximately 9 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 Umatilla

In Umatilla in May, humidity is 68%. With an average temperature of 25°C (77°F), this humidity feels like a warm embrace that can quickly become stifling for traveling, making outdoor activities feel more strenuous and the air thick and heavy.

May Average Humidity in Umatilla

This chart illustrates the average monthly humidity levels in Umatilla, 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 Umatilla is approximately 68%, 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 Umatilla

In Umatilla in May, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Umatilla.

Maximum UV Index Levels in Umatilla for May

The chart shows the monthly maximum UV Index (UVI) for Umatilla 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 Umatilla typically reaches 11, which falls under the extreme exposure category.

Data source: Umatilla 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 Umatilla Compares to Other Months

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

This table compares monthly weather conditions in Umatilla, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	15°C (59°F)	47 mm (1.9 inches)	83%	moderate
February Weather	18°C (65°F)	57 mm (2.2 inches)	80%	very high
March Weather	19°C (67°F)	25 mm (1.0 inches)	75%	very high
April Weather	22°C (72°F)	80 mm (3.2 inches)	70%	extreme
May Weather	25°C (77°F)	97 mm (3.8 inches)	68%	extreme
June Weather	27°C (81°F)	190 mm (7.5 inches)	75%	extreme
July Weather	27°C (82°F)	221 mm (8.7 inches)	79%	extreme
August Weather	28°C (82°F)	203 mm (8.0 inches)	81%	extreme
September Weather	27°C (81°F)	153 mm (6.0 inches)	83%	extreme
October Weather	25°C (77°F)	80 mm (3.1 inches)	81%	very high
November Weather	19°C (67°F)	58 mm (2.3 inches)	82%	high
December Weather	17°C (62°F)	71 mm (2.8 inches)	84%	moderate