Increasing Number of Summer Heat Waves in Israel, Study Finds

Meteorological Service says period between heat waves is now every 6 to 6.5 days, up from every 8 to 9 days between 1950-1980.

Zafrir Rinat
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A Tel Aviv beach.
A Tel Aviv beach. Credit: Tomer Appelbaum
Zafrir Rinat

Israel has been subject to an increasing number of summer heat waves over the last two decades, according to a Meteorological Service study.

The study covered weather patterns over most of the last century (1920-2015), measured at 18 stations across Israel. There were no statistical changes in the number of extreme rainstorms or snowfall.

Heat waves are defined as occurring when the average daily temperature rises by 6 degrees Celsius, on average, for three consecutive days.

This increase in the frequency of heat waves matches the general upward trend in average temperatures at the time.

According to the measurements of the Jerusalem weather station, the time period between such events during June-September in 1950-1980 was eight to nine days. However, this had dropped to every six to six-and-a-half days in the past two decades.

In North America and Europe, such heat waves have been known to increase fatalities among at-risk populations such as the elderly. They also lead to an increase in major wildfires due to a drying up of forests. Another consequence is the surge in power consumption as people turn on their air-conditioning.

Despite some heavy snowfall in Israel in recent years, these were not deemed statistically significant. There has been more light snowfall (defined as up to 1 centimeter, or 0.4 inches), but this was not considered extreme weather.