Armagh Observatory, 11th November 2021:  Armagh Observatory reports that October 2021 was much warmer and sunnier than average, with roughly average rainfall.  This was the warmest October at Armagh for 15 years.

The mean temperature was approximately 12.0 degrees Celsius (53.6 Fahrenheit), which is nearly 2.55 C warmer than the 183-year long-term (1796-2020) average October temperature at Armagh and 1.66 C warmer than the most recent (1991-2020) 30-year average.  This was the warmest October at Armagh for 15 years, that is, since October 2006 (12.1 C).

The warmest day (highest maximum air temperature) was 20.3 C on the 7th, followed by 19.8 C on the 19th.  The coldest day (lowest maximum air temperature) was 11.5 C on the 30th, followed by 12.3 C on the 31st.

The highest minimum air temperature or warmest night was 15.6 C, which occurred around 09:00 GMT on the morning of the 8th, followed by 14.1 C, which occurred around 19:50 GMT on the night of the 18th/19th.  The coldest night, that is, the lowest minimum temperature, was 2.5 C on the 15th followed by 4.0 C on the 21st.

There were just two ground frosts this month, that is, nights with grass minimum temperatures less than or equal to zero Celsius, namely -1.7 C on the 15th and -0.2 C on the 31st.  There were no air frosts.

It is noteworthy that although, on average, the mean monthly temperatures at Armagh are slowly increasing, the average increase for October is less than for any other calendar month.  For example, whereas the October (1961-1990) 30-year average is approximately 10.1 C and the (1991-2020) 30-year average is 10.4 C, the corresponding figures at Armagh for the adjacent months September and November are 12.8 C and 13.5 C and 6.1 C and 7.3 C respectively.

Total precipitation was 80.5 mm (3.17 inches) including 4 trace values, that is, 80.3 mm if trace values are ignored.  This may be compared with the 183-year long-term (1838-2020) average October precipitation at Armagh (80.40 mm) and the most recent (1991-2020) 30-year average (81.0 mm), showing that this year’s October precipitation was very close to average.  The wettest day was 13.8 mm (0.54 inches) on the 30th followed by 9.1 mm (0.36 inches) on the 26th.

This was a relatively calm month with no named autumn storms seriously affecting either this part of the UK or Ireland.  Rainbows were recorded on the 17th, 19th, 20th, 21st and 24th. Five fieldfares, a species of medium-to-large migratory thrush that normally overwinters between late October and March, were observed near the weather station feeding on the morning of the 5th.

With a total of 105.7 hours of strong sunshine, October 2021 was sunnier than average, registering approximately 21% more strong sunshine than the 140-year long-term (1881-2020) average at Armagh and 15% more than the most recent (1991-2020) 30-year average.  The sunniest day, with 7.7 hours of strong sunshine, was the 15th, followed by 7.4 hours on the 10th.

These data refer to observations at Armagh Observatory, which has been recording the weather at Armagh since 1795.


For further information, please contact:

Professor Mark E. Bailey

Emeritus Director of Armagh Observatory

Armagh Observatory and Planetarium

College Hill


BT61 9DG


Tel: 028-3752-2928

E-mail: mark.bailey@armagh.ac.uk


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