May Weather in St Johnsbury, United States

Last updated: June 24, 2025

In May, the average temperature in St Johnsbury, United States hovers around 12°C (55°F), offering a mild climate for visitors. However, be prepared for temperature fluctuations, as it can dip to a chilly -1°C (30°F) or soar to a warm 32°C (90°F). The region experiences an average precipitation of 95 mm (3.7 in) over 12 days, contributing to a relatively high average humidity of 78%. Whether you're exploring the outdoors or seeking indoor activities, this diverse weather can add a unique twist to your experience!

May Temperature in St Johnsbury

In May in St Johnsbury, the average temperature is 12°C (55°F). The maximum can reach 32°C (90°F), and the minimum can be as low as -1°C (30°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

May Weather in St Johnsbury: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in St Johnsbury, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In St Johnsbury, May typically has an average temperature of 12°C (55°F), with highs reaching up to 32°C (90°F) and lows dropping to around -1°C (30°F).
JanFebMarAprMayJunJulAugSepOctNovDec182128425463686659483323
Data source: Temperature data for St Johnsbury generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in St Johnsbury

In St Johnsbury in May, the precipitation amount is 95 mm (3.7 in) over the course of 12 days.

May Precipitation Trends in St Johnsbury

The chart displays monthly precipitation patterns in St Johnsbury, 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 St Johnsbury, May typically receives around 95 mm (3.7 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec8078691109598106886413910385
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in St Johnsbury

In St Johnsbury in May humidity is 78%. With average temperature 12°C (55°F), this humidity feels like a damp chill that wraps around you, making outdoor activities less enjoyable and travel a bit uncomfortable unless you're layered appropriately.

May Average Humidity in St Johnsbury

This chart illustrates the average monthly humidity levels in St Johnsbury, 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 St Johnsbury is approximately 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%85%84%78%72%75%74%77%85%86%85%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in St Johnsbury

In St Johnsbury in May, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in St Johnsbury.

Maximum UV Index Levels in St Johnsbury for May

The chart shows the monthly maximum UV Index (UVI) for St Johnsbury 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 St Johnsbury typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2458910997532
Data source: St Johnsbury 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 St Johnsbury Compares to Other Months

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

This table compares monthly weather conditions in St Johnsbury, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-8°C (18°F)80 mm (3.1 inches)91%low
February Weather-6°C (21°F)78 mm (3.1 inches)89%moderate
March Weather-2°C (29°F)69 mm (2.7 inches)85%moderate
April Weather5°C (42°F)110 mm (4.3 inches)84%very high
May Weather12°C (55°F)95 mm (3.7 inches)78%very high
June Weather17°C (63°F)98 mm (3.9 inches)72%very high
July Weather20°C (69°F)106 mm (4.2 inches)75%very high
August Weather19°C (67°F)88 mm (3.5 inches)74%very high
September Weather15°C (60°F)64 mm (2.5 inches)77%high
October Weather9°C (48°F)138 mm (5.5 inches)85%moderate
November Weather0°C (33°F)103 mm (4.0 inches)86%moderate
December Weather-5°C (23°F)85 mm (3.3 inches)85%low

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