However pay attention to possible thunderstorms that may occur in the evening. Lisbon has long hot summers, pleasantly warm springs/autumns and mild, but possibly wet winters. The height of the tourist season is from June until the end of September, while the beaches are at their busiest in July and August. The average sea surface temperature in August 2020 for Lisbon was 72.5°F.The maximum and minimum values were 71.2°F and 74.6°F respectively. Almost anything done during August will be pleasurable. Averages are for Lisbon Portela Airport, which is 3 miles from Lisbon. more about this country January February March April May June July August September October November December; Avg. The climate in Lisbon during August can be summarized as warm and reasonably dry. The average minimum temperature (usually the minimum temperature is noted during the night) in Lisbon in August is 19.0°C (66.2°F). This is usually the best time to go to the beach to get a tan or swim as the water is relatively warm. August is a dry month with an average of 6mm (0.2in) rain. however as they disappear discreetly at the same time as the heat, one can still enjoy a magnificent weather in Lisbon throughout August for the rest of the day. The average maximum temperature lies around 28.0°C (82.4°F). Search. Lisbon is situated in Mediterranean climate zone that typically has warm or hot summer with mild rains and soft but rainy winter. The mean temperature is 73°F (22.8°C). The weather is suitable for spending time on Lisbon’s beaches from May until the middle of September. The fogs intensify and persist for hours. Lisbon at the End of August To help you choose the best time to travel, you can find climate data below on the weather in Lisbon in August. Showing: All Year January February March April May June July August September October November December Temperature (°C) 11.7 12.4 13.8 15.4 17.5 20.1 22.4 22.7 21.6 18.7 Lisbon, Portugal - Travel and vacation weather averages, current conditions and forecasts. [1801825] Average Weather during August in Lisbon (Lisbon Region), Portugal. Tourists begin to flock into Lisbon to enjoy the summer festivals and the pleasant weather. Last 2 weeks of weather Based on weather reports collected during 1985–2015. °F. Portugal. Daytime maximum temperatures average around a comfortable 28°C (82°F), whilst at night 12°C (54°F) is normal. Lisbon in the Middle of August. Toggle navigation. August is in the summer in Lisbon and is typically the 2nd warmest month of the year. Lisbon Extended Forecast with high and low temperatures. July and August are the hottest months as the temperatures soar to sometimes 43°C (109°F). Weather Atlas: Lisbon, Portugal - August weather forecast and climate information. August weather forecast for Lisbon, Portugal.