November was very rainy as measured at the “Italia Costa Rica” Biological and Meteorological Experimental Research Station. Due to the landfall north of Costa Rica of two catastrophic hurricanes, Eta and Iota, which also gave an indirect influence on the Nicoya peninsula in November 2020, a total of 325.6 mm fell.
From the climatological data reconstructed with the Meteoblue reanalysis, in the period 1986-2015 the average rainfall in November was 191.0 mm. Our station has only been in operation since 2016 and fully operational since February 2017, in this period we had never seen so much rainfall.
The average monthly temperature was affected by heavy rain and scarce sunshine and is therefore 25.0° C, the lowest value in our short series of data, but still higher than the 1986-2015 average obtained from the renanalysis which is 24.6 ° C.
The wettest day of the month was the 22nd, with 51.6 mm, the lowest minimum temperature of 19.3 ° C on the 19th and the highest maximum temperature of 31.7 ° C on the 26th.
The anomalous rainy situation had as a consequence the delay in the arrival of the dry season, in the month there are in fact 26 days with measurable rainfall, also given the first data of December, the rainy season seems to have ended with the showers of 27-28 November.
So far we had observed rains until day 22 in 2017, until 17 in 2018 and until 11 in 2019, in these two years some rains followed even at the end of the month, but of an isolated character while in this 2020 the rainfall was substantially daily until the end of the month.
Trend of temperature (red line) and rainfall in 24 hours at the Karen Mogensen reserve, Costa Rica in November 2020.