Q COSTA RICA — Costa Rica will experience an increase in temperatures and a reduction in rainfall due to a combination of Saharan dust, the midsummer heat wave (la canícula), and conditions associated with the El Niño phenomenon.
The national weather service, the Instituto Meteorológico Nacional (IMN), forecasts that these conditions will begin to intensify toward the end of July and persist through much of August, when drier weather is expected across much of the country.
Adding to this scenario will be the arrival of new masses of Saharan dust during both months, a common phenomenon at this time of year that will favor clearer skies, higher temperatures, and a lower chance of precipitation.
“We are anticipating an increase in particulate matter in the atmosphere this weekend. It is normal for Saharan dust masses to arrive in both July and August. This favors clearer conditions, warmer temperatures, and less rainfall,” explained Daniel Poleo of the IMN.
Poleo explained that new pulses of Saharan dust will enter the country in the coming weeks, a phenomenon characteristic of the rainy season. “We anticipate an increase in particulate matter in the air over the weekend, exacerbated by stronger trade winds, which will also lead to a decrease in air quality,” the specialist indicated.
The presence of Saharan duct can primarily affect the most vulnerable groups, such as children, the elderly, and people with allergies or respiratory illnesses. Although Saharan dust is a recurring phenomenon during July and August, the El Niño context can increase the frequency of these episodes.
Heat could reach 38°C
On the other hand, experts predict an increase in temperatures for the rest of the week.
“A decrease in humidity in the Caribbean Sea basin due to the arrival of a dusty air mass will reduce instability in the region. This will also intensify the high temperatures and muggy conditions characteristic of this hot and dry month, which falls within the context of this year’s El Niño,” the IMN highlighted.
By region, the following is forecast:
- North Pacific: highs could reach 38°C
- South Pacific: highs could reach 34°C
- Central Pacific and Northern Zone: highs of up to 33°C
- Central Valley and Caribbean: highs near 31°C
Second phase of the midsummer heat wave
According to the IMN, during the week of July 20-26, typical seasonal conditions will prevail in the Pacific, Central Valley, and Northern Zone.
The most significant change will begin to be felt starting July 27, when the second phase of the midsummer heat wave will intensify.
“From then on, rainfall will decrease in the Pacific, Central Valley, and Northwest Zone. The deficit could increase during the first two weeks of August,” the National Meteorological Service forecasts.
Between August 3 and 16, the North Pacific and Central Pacific could experience very dry conditions. The South Pacific and Central Valley will maintain a dry pattern.
In contrast, the North Caribbean will continue to experience rainy conditions until August 9. After that, rainfall will return to normal levels for this time of year.
