Portsmouth Monthly Rainfall & Precipitation
This page shows both the average monthly rainfall and the number of rainy days in Portsmouth, Dominica. Long-term data from 1990 to 2020 was used to calculate these averages. Now, let's break down all the details for a clearer picture.
On average, Portsmouth receives a reasonable amount of rainfall, with an annual precipitation of 973 mm (38 in). Despite this overall moderate level, the city experiences distinct dry season during certain months throughout the year, as illustrated in the precipitation charts below.
Monthly Precipitation Levels
The average number of days each month with precipitation (> 0.2 mm (0.01 in))
Portsmouth can be quite wet during October, receiving approximately 137 mm (5.4 in) of precipitation over 19 rainy days.
In contrast March, experiences much drier conditions, with 33 mm (1.3 in) of rainfall, spread across 15 rainy days.
October, the wettest month, has a maximum daytime temperature of 29°C (84°F). The city receives 220 hours of sunshine in this period. During the driest month March you can expect a temperature of 27°C (81°F). For more detailed insights into the city's temperatures, visit our Portsmouth Temperature page.
Explore Portsmouth's Historical Precipitation: 1976-2026
Browse day-by-day precipitation records for Portsmouth spanning 51 years. Select any month and year to see actual rainfall and snowfall recorded on each day.
Annual Rainfall in Dominica: City Comparison
The map below shows the annual precipitation across Dominica. You can also select the different months in case you are interested in a specific month.
heavy rainfall
high
moderate
low
almost none
Portsmouth vs World: Rainfall Compared
Portsmouth's average annual precipitation is 973 mm (38 in). Let's compare this to some popular worldwide tourist destinations:
Seville, Spain, experiences 541 mm (21 in) of rainfall annually, with wet winters and dry summers typical of southern Spain.
Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.
Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.
Mumbai, India, experiences a tropical monsoon climate with 1860 mm (73 in) of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.
Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.
Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.
- Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
- In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
- Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.
For more detailed information about Portsmouth's weather, including sunshine hours, humidity levels, and temperature data, visit our Portsmouth Climate page.
