If you have been feeling extra hot and sweaty this month, you are probably not alone.

Last month was the hottest September in recorded history.

"Bananas" temperatures

Climate scientist Zeke Hausfather, who was a contributing author for the Intergovernmental Panel on Climate Change's (IPCC) Sixth Assessment Report (AR6), described September's weather as "absolutely gobsmackingly bananas” in a post on X (formerly Twitter).

Data from the Japanese 55-year Reanalysis (JRA-55), a climate dataset covering the period from 1958, showed that the temperature anomaly in 2023 has been on the rise since the start of the year, and that it far exceeds the temperature anomalies of previous decades.

The first global temperature data is in for the full month of September. This month was, in my professional opinion as a climate scientist – absolutely gobsmackingly bananas. JRA-55 beat the prior monthly record by over 0.5C, and was around 1.8C warmer than preindutrial levels. pic.twitter.com/mgg3rcR2xZ

— Zeke Hausfather (@hausfath) October 3, 2023

Hausfather also noted in his tweet that September 2023 beat the previous record for that month by 0.5°C. It was also around 1.8°C warmer than pre-industrial levels.

The Paris Agreement aims to keep global temperature rise to well below 2ºC, or if possible, 1.5ºC above pre-industrial levels in the year 2100.

An image of a heat map from the JRA-55 that Hausfather posted also showed that daily temperatures in September "stand out like a sore thumb", compared to previous months.

Similarly, we can look at a heatmap of every day of the year so far, where September stands out like a sore thumb: pic.twitter.com/kdOQwylmdQ

— Zeke Hausfather (@hausfath) October 3, 2023

And finally, here are all the daily temperatures since the JRA-55 record began, putting this year's extreme warmth into context: pic.twitter.com/RSQC3TZ6yP

— Zeke Hausfather (@hausfath) October 3, 2023

2023 is on track to be the hottest year in recorded history, according to the European Union’s Copernicus Climate Change Service, which publishes monthly climate bulletins on global surface air temperature, sea ice cover and other variables.

The latest update on Oct. 5 reported that global average surface air temperature in September reached 16.38°C. This is 0.93°C above the 1991-2020 average for September, and beat the previous monthly record set of September 2020 by 0.5°C.

Additionally, September 2023 global temperature was the "most anomalous warm month of any year" from 1940.

In Singapore, the highest daily maximum temperature recorded in September was 34.9°C at Sentosa on Sep. 19, 2023.

Why is it so hot?

With climate change and the onset of the natural climate phenomenon, El Niño, the heat has been unrelenting.

El Niño is a phenomenon that leads to warming of waters in the Pacific ocean and increasing temperatures.

In Southeast Asia, El Niño typically brings drier and warmer weather.

Previously, the Meteorological Service Singapore (MSS) announced in August the start of El Niño in Singapore.

Minister for Sustainability and the Environment Grace Fu also stated during September's Parliamentary sitting that El Niño is expected to last till at least early 2024.

March 2024 to April 2024 could see the warmest temperatures, she added.

Extreme weather events

Climate change is known to bring about extreme weather events.

Thousands have been killed following a flash flood in Libya, and violent storms caused floods in Greece, Bulgaria and Turkey, reported CNN and The New York Times.

Canada has been plagued with its worse wildfire season, with the smoke reaching as far as the U.S. state of Florida.

Canadian Prime Minister Justin Trudeau in June attributed the increase in the number of wildfires to climate change, reported Reuters.

However, a research scientist with the Canadian Forest Service said it is difficult to determine the impact of climate change on a single fire season.

Top photo from Unsplash