Climate Overview
The climate in Oeiras is hot. The average annual temperature is 28°C and approximately 773mm of precipitation falls per year. March is the wettest month, receiving around 193mm of rainfall. Oeiras sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Oeiras sees moderate temperature variation throughout the year, ranging from 22°C to 37°C. October is the hottest month, with daytime highs reaching 37°C and an average of 31°C. July is the coolest month, with minimum temperatures around 22°C and an average of 28°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs.
Precipitation
Oeiras is a relatively dry area, receiving approximately 773mm of precipitation annually, which averages out to around 64mm per month. The wettest month is March, averaging 193mm of rainfall. February and January also tend to see above-average precipitation. The driest month is August, with just 0mm. That's 193mm less than March, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Oeiras is mildly breezy, with an average annual wind speed of 15km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is July, averaging 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in February, with average winds dropping to 10km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 11km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 20km/h in winter, 16km/h in spring, 11km/h in summer, 13km/h in autumn.
Seasons
88 days until Winter
It is currently autumn in Oeiras, which began on March 20, 2026. Oeiras sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in October at around 37°C, while the coldest stretch bottoms out in July near 22°C. Winter is next, beginning on June 21, 2026 — 88 days from now.
Spring
Temperatures range from 25 to 37°C. Rainfall is relatively light, with around 60mm over the season and a monthly average of 20mm. Winds are moderate at around 16km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 23 to 34°C. Rainfall is heavy, totalling around 407mm across the season with a monthly average of 136mm. Winds are generally light, averaging 11km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 23 to 33°C. Precipitation is moderate at around 301mm for the season, averaging 100mm per month. Winds are generally light, averaging 13km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 22 to 35°C. Precipitation is minimal, with only around 4mm for the entire season. Winds are moderate at around 20km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Oeiras based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
