Summer 2026 - Warsaw weather summary

In most part of Europe, the summer of 2026 was the hottest since records began. The continent was plagued by seven heatwaves:
1. Late May – hit Western Europe, in Warsaw temperature did not exceed +29C.
2. Late June – lengthy, the most intense and severe, in many spots, including Warsaw, the toughest since records began and record-breaking.
3. Mid-July – moderate, in Warsaw temperature topped above +30C once, on 17 July.
4. Early August – severe, lengthy, but not record-breaking in most areas, yet affected Poland.
5. Mid-August – short, intense, in Warsaw one day-time high above +30C on 15 August.
6. Late August – hit southern Europe most. In Warsaw temperature did not rise above +27C.
7. Early September – affected Western and central Europe. In Warsaw two days with maximum temperatures above +28C.

As seen in the summary above, Poland had to endure only two dreadful heatwaves and basically was treated relatively mildly, comparing to thermal shocks in France, the UK, Austria or Hungary.

All in all, with:
- June 2.4 Celsius degrees warmer, July 0.3 Celsius degrees colder and August 1.0 Celsius degrees warmer than long-term average (1991 – 2020), the entire summer was warmer than long-term average (+19.9C vs. +18.8C benchmark), but still reasonably cooler than the warmest 2024 summer (mean temperature: +21.1C) and eighth warmest since records began.

Heat records in Poland were broken during both intense heatwaves, with Warsaw setting a new all-time maximum temperature record of +38.1C. It will be difficult to beat, but sadly, a new record is just a matter of time.

In 2026 Warsaw recorded 3 days with highs above +35C (in 1994 there were four such days).

On 18 days maximum temperatures exceeded +30C. This is fewer than in 2024 (24), 2015 (also 24), 2006 (22), 2022 (19), 1994 (19) and at the par with 2019 and 1992. Of note – before 1990 the maximum number of hot days did not exceed 16 in a year.

Warsaw also endured 9 tropical nights (record from 2019 tied), including the most awful one, with minimum temperature of +24.7C (previous record beaten by +1.9 Celsius degrees).

Rainfall-wise, at first sight the situation wasn't disturbing. In June total precipitation reached 94% of long-term average, in July – 137% and in August – 135%. Nonetheless, preceding winter and spring were exceptionally dry and summer rains, including downpours, could not make up for it. Hydrological drought, in place in Poland since approximately 2014, has got only worse. These days level of Wisła is hitting all-time lows, with flow of water also being historically slow.

Looking ahead, the biggest puzzle is the indirect impact of probably the strongest El Nino ever on weather in Poland. Temperature of waters in Pacific does not influence weather in Europe much, but most forecasts hint at increased North Atlantic Oscillation, which would bring warm, plausibly the warmest on the record and rainy winter into Europe. Bearing in mind bleak prospects of war in Ukraine, rising natural gas prices and low level of gas stores kept in Europe, I keep fingers crossed for a mild winter.