I have used my 13-year weather record to find the number of hot days in each year and in each month. Earlier I did the same for frosty mornings. Because the summer, which has the most hot days, crosses from one calendar year to the next, I have begun each year at July.
I have called days warmer than 35° “hot days”, and days warmer than 40° “very hot days”.

Total hot days

The first graph shows the number of hot and very hot days in each year. The most hot days were in the year ’09-’10, which had 44; the fewest were in the year ’11-’12, which had only 4. The 13-year average is 26, but the number of hot days is quite different from year to year.

Counting only the very hot days, ’03-’04 had the most (6), and four years had none at all. On the average, two days exceeded 40° in a year.

Months with hot days

The second graph shows how the number of hot and very hot days peaks strongly in January, with very few earlier than November or later than March. On average, Manilla’s summer has about 22 days warmer than 35°, while spring has 3, and autumn only 1.

The other graphs show how each year had a different pattern of hot days. The highest monthly peaks, each 19 hot days, came in January 2003 (following drought) and January 2007. Annual peaks also came in January in 2008 and 2012, but these peaks were extremely low: only 4 and 3 hot days.

Peak numbers of hot days came as late as February in three of the years, and as early as December in one.
The year ’09-’10 was strange: the peak came in November 2009. December and January also had many hot days, but February had few.

Of the 26 days on record that are warmer than 40°, half of them occurred in January months, including five in January 2003. Four others were in November 2009, including the hottest: 42.6°.

This article appeared in “The Manilla Express” for  27th November 2012, and also as a “weatherzone” forum post dated 29th June 2012.

I have posted it on this blog back-dated to 30th June 2012, but made sticky on 6th July 2014.