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May Weather in Heidelberg, United States

Last updated: June 24, 2025

In May, the average temperature in Heidelberg, United States hovers around 23°C (74°F), with minimums dipping to 8°C (47°F) and maximums soaring to 35°C (96°F). Expect about 137 mm (5.4 in) of precipitation over 12 days, contributing to an average humidity of 73%, creating a humid yet vibrant atmosphere.

May Temperature in Heidelberg

In May in Heidelberg, the average temperature is 23°C (74°F). The maximum can reach 35°C (96°F), and the minimum can drop as low as 8°C (47°F). This variety in temperatures makes Heidelberg a suitable destination for travelers seeking both warm days and cooler evenings.

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

The chart illustrates May temperature patterns in Heidelberg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Heidelberg, May typically has an average temperature of 23°C (74°F), with highs reaching up to 35°C (96°F) and lows dropping to around 8°C (47°F).
JanFebMarAprMayJunJulAugSepOctNovDec495561657479818178705652
Data source: Temperature data for Heidelberg 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 Heidelberg

In Heidelberg in May, the precipitation amount is 137 mm (5.4 in) that occurs over the course of 12 days.

May Precipitation Trends in Heidelberg

The chart displays monthly precipitation patterns in Heidelberg, 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 Heidelberg, May typically receives around 137 mm (5.4 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec110140121127137168137132979972133
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Heidelberg

In Heidelberg in May, humidity is 73%. With an average temperature of 23°C (74°F), this humidity feels like a warm, enveloping blanket, making traveling a bit sweaty and heavy, but still pleasant if you stay hydrated and take breaks in the shade.

May Average Humidity in Heidelberg

This chart illustrates the average monthly humidity levels in Heidelberg, 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 Heidelberg is approximately 73%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%78%73%71%79%78%80%76%83%87%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Heidelberg

In Heidelberg 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 Heidelberg.

Maximum UV Index Levels in Heidelberg for May

The chart shows the monthly maximum UV Index (UVI) for Heidelberg 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 Heidelberg typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec478111111111110864
Data source: Heidelberg 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 Heidelberg Compares to Other Months

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

This table compares monthly weather conditions in Heidelberg, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (50°F)110 mm (4.3 inches)82%moderate
February Weather13°C (55°F)140 mm (5.5 inches)80%high
March Weather16°C (61°F)121 mm (4.7 inches)80%very high
April Weather18°C (65°F)127 mm (5.0 inches)78%extreme
May Weather23°C (74°F)137 mm (5.4 inches)73%extreme
June Weather26°C (79°F)168 mm (6.6 inches)71%extreme
July Weather27°C (81°F)137 mm (5.4 inches)79%extreme
August Weather27°C (81°F)132 mm (5.2 inches)78%extreme
September Weather26°C (78°F)97 mm (3.8 inches)80%very high
October Weather21°C (70°F)99 mm (3.9 inches)76%very high
November Weather13°C (56°F)72 mm (2.8 inches)83%high
December Weather11°C (53°F)133 mm (5.3 inches)87%moderate

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