March Weather in Portsmouth, United States

Last updated: June 24, 2025

In March, the average temperature in Portsmouth, United States hovers around 10°C (51°F). Temperatures can be quite variable, with a minimum dipping to -5°C (24°F) and a maximum soaring to 30°C (85°F). Expect 79 mm (3.1 in) of precipitation over approximately 10 days, accompanied by a notable average humidity of 82%. Get ready for a month of diverse weather!

March Temperature in Portsmouth

In March in Portsmouth, the average temperature is 10°C (51°F). Maximums can reach 30°C (85°F) and minimums can be as low as -5°C (24°F). Be prepared for a wide range of temperatures, making it essential to pack layers for your travels.

March Weather in Portsmouth: Daily Temperature Highs, Lows, and Averages

The chart illustrates March temperature patterns in Portsmouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Portsmouth, March typically has an average temperature of 10°C (51°F), with highs reaching up to 30°C (85°F) and lows dropping to around -5°C (24°F).

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

March Precipitation in Portsmouth

In Portsmouth in March, the precipitation amount is 79 mm (3.1 in) over a span of 10 days.

March Precipitation Trends in Portsmouth

The chart displays monthly precipitation patterns in Portsmouth, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In Portsmouth, March typically receives around 79 mm (3.1 inches) of precipitation spread over approximately 10 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

March Humidity in Portsmouth

In Portsmouth in March humidity is 82%. With an average temperature of 10°C (51°F), this humidity feels like a damp chill that clings to your skin, making outdoor adventures less appealing and prompting travelers to seek cozy indoor activities or warm drinks to counter the brisk air.

March Average Humidity in Portsmouth

This chart illustrates the average monthly humidity levels in Portsmouth, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in Portsmouth is approximately 82%, offering insight into how humid the weather typically is during this month.

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

March UV Index in Portsmouth

In Portsmouth in March, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Portsmouth.

Maximum UV Index Levels in Portsmouth for March

The chart shows the monthly maximum UV Index (UVI) for Portsmouth in March, 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 March, the maximum UV index in Portsmouth typically reaches 8, which falls under the very high exposure category.

Data source: Portsmouth March 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 March Weather in Portsmouth Compares to Other Months

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

This table compares monthly weather conditions in Portsmouth, showing how March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	6°C (43°F)	90 mm (3.5 inches)	84%	moderate
February Weather	8°C (47°F)	99 mm (3.9 inches)	83%	high
March Weather	10°C (51°F)	79 mm (3.1 inches)	82%	very high
April Weather	16°C (60°F)	97 mm (3.8 inches)	81%	very high
May Weather	20°C (69°F)	121 mm (4.7 inches)	80%	very high
June Weather	24°C (76°F)	121 mm (4.8 inches)	82%	very high
July Weather	27°C (81°F)	142 mm (5.6 inches)	81%	extreme
August Weather	26°C (79°F)	169 mm (6.6 inches)	81%	very high
September Weather	24°C (75°F)	127 mm (5.0 inches)	78%	very high
October Weather	19°C (66°F)	91 mm (3.6 inches)	80%	very high
November Weather	11°C (53°F)	78 mm (3.1 inches)	84%	moderate
December Weather	8°C (47°F)	89 mm (3.5 inches)	84%	moderate