Romania’s Heat Wave Evolution: A 70-Year Analysis

The data on the evolution of heat waves in Romania and Eastern Europe, during the last 70 years or so, show a statistically significant increase in the length and frequency of heat waves for the period 1950-2023.

Between May 31 and July 31, 2024, Romania was hit by the longest and most intense heat wave in recent history. Of these 62 days, 46 recorded heatwave conditions, which is 75% of the entire period.

• The first heat wave occurred between 31 May and 13 June 2024 recorded at the Bucharest Filaret meteorological station, and lasted 14 days, with a cumulative intensity of 114.04 °C.
• The second wave, which took place between June 16 and 21, had an intensity of 115.34°C and lasted 16 days.
• The most intense heat wave was recorded between July 6 and 21, with a cumulative intensity of 152.02°C, a record for the last 130 years.

In the months of June and July 2024, 57 days with a maximum daily temperature above 30 °C, 28 days with a temperature above 35 °C and 6 days with a temperature above 40 °C were recorded at Bucharest Filaret station.

The Heat Wave in the Second Half of July Affected the Whole Country

These values are unprecedented in over 130 years of observations at this station. The heat wave in the second half of July affected the whole country, with the highest temperatures being recorded in the non-Carpathian regions. On July 16, 2024, 24 weather stations recorded temperatures above 40 °C, and on July 17 in 17 stations.

In the period July 1-18, 2024, in 26 stations the highest absolute monthly temperature was equal or higher, with examples such as Botoșani (+39.4°C) and Târgu Mureș (+39.0°C).

Even the mountainous areas were affected, with Brașov registering +36.6°C and Predeal +31.4°C. Globally, data from atmospheric analyzes operated by Copernicus satellites show that July 22, 2024 was the warmest day in the world since at least 1940, with a global average temperature of +17.16°C.

This was closely followed by 23 July, with +17.15°C. Before July 2023, the previous record was +16.8°C, set on August 13, 2016. Between July 3, 2023 and July 23, 2024, this record was broken 59 times. The 2024 heat wave is not an anomaly but reflects an evolution confirmed by empirical data.

Analysis of the Evolution Over Time

The data shows that there is a statistically significant increase in Romania in the length and frequency of heat waves.

Most regions have seen an increase in the length of heat waves between 10 and 15 days over the last 74 years, while the south-west and east of the country (near the Black Sea) have seen an increase of more than 25-30 days.

In terms of the frequency of heat waves, there is a significant increase throughout the country, and the most affected counties are Mehedinți, Dolj, Brăila, Galați, Maramureș, Bacău and Neamț. For example, in the counties of Mehedinți and Dolj, there has been an increase of 4 heat waves during the last 74 years.

Romania’s Notable Increase in Average Temperature

Between 1958 and 2023, the average annual temperature of Romania increased by about +2.11°C, an increase of +0.30°C above the global average temperature (+1.81°C) and +0.12°C above the average temperature in Europe (1.99°C).

• This warming trend has led to more frequent and longer heat waves, especially during the summer months. Heat waves have serious consequences for people’s health, increasing the risk of heat stroke, dehydration and cardiovascular problems, especially among the elderly and children.
• They also affect agriculture, endanger food security, exacerbate drought, deplete water resources and increase the risk of wildfires.
• These challenges underline the need for urgent measures and effective mitigation strategies to protect the population and the environment.

Climate forecasts for Romania show a continuation of the warming trend and an increase in the frequency and intensity of extreme events, especially heat waves and droughts.

These changes have profound consequences for the environment, agriculture and human well-being. Understanding the basic scientific evidence and possible future impacts is essential to developing effective mitigation and adaptation strategies for our country’s climate change.