Porto-Novo Climate Trends
Benin · Africa · 50 years of climate trend data
This page tracks how Porto-Novo's climate has shifted over 50 years of daily measurements, warmer summers, milder winters, and changes in rainfall, rather than current conditions. The two clearest signs of change: extremely hot days have grown by 118.2 a year and heavy-rain days have grown from 4.8 to 8.4 a year. Measurement period: the last 50 years (1976-2025).
Data through September 13, 2026.
Frequently asked questions about Porto-Novo's climate
How much warmer have summers in Porto-Novo become?
The average daytime high across June, July and August rose by 1.1°C between 1976-1980 and 2021-2025. That is a five-year average at each end rather than two isolated summers, so a single exceptional heatwave or cool summer does not drive the number.
Have winters in Porto-Novo become milder?
The average daytime high across December, January and February rose by 1.7°C between 1976-1980 and 2021-2025. In many capitals in this dataset winter is changing faster than summer, which shows up most clearly in the frost-day count below.
How many days above 30°C does Porto-Novo get a year?
Porto-Novo averaged 125 days a year above 30°C in 2021-2025, up from 7 in 1976-1980. These are the days that set peak cooling demand and the days hospitals see heat complaints rise.
How many frost days does Porto-Novo still get?
Porto-Novo does not drop below freezing in any year of this record, not in 1976-1980 and not in 2021-2025. Frost is not a useful measure of change here, though the heat figures above are.
Is spring arriving earlier in Porto-Novo?
Spring now starts about 0.1 weeks earlier than in 1976-1980. The start point is the first day the trailing seven-day average high crosses 12°C, a fixed in-house measure used only to compare Porto-Novo against itself rather than against other cities.
Has the growing season in Porto-Novo grown longer?
The growing season here is measured as the stretch between the start of spring and the first autumn night below freezing. Porto-Novo has no reliable autumn frost in this record, so that measure yields no meaningful number.
Is rainfall in Porto-Novo getting heavier?
Porto-Novo averaged 8.4 days a year with more than 20mm of rain in 2021-2025, up from 4.8 in 1976-1980. Warmer air holds more water vapour, so the same annual rainfall increasingly arrives in shorter, harder bursts, which loads drains and water storage more than the annual total suggests.
