Driest April in 35 years; dullest in 20 years

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The Armagh Observatory has reported that April 2017 was much drier than average, and slightly warmer and much duller.

This was the driest April at Armagh for 35 years and the sixth-driest April at Armagh since rainfall records began in 1838.

It was also the dullest April at Armagh for 20 years.

Following a very dry autumn 2016 and winter 2016/2017, this year has seen the driest eight month period, September through April, at Armagh for 83 years, and the driest August through April nine month period for the same time.

Total April precipitation was just 9.2 mm (0.36 inches), including 10 trace values.

This is approximately 1/6 of the average April rainfall at Armagh.

The wettest day was the 22nd, with 2.1 mm (0.08 inches) of rainfall.

April 2017 also saw very few hours of strong sunshine, with just 96.3 hours recorded at Armagh.

This was the dullest April at Armagh for 20 years, that is, since April 1997, and the seventh-dullest April at Armagh since sunshine records began at the Observatory around 1881.

This April had only two-thirds of the most recent (1981–2010) 30-year average April sunshine at Armagh.

The sunniest day was the 25th with 12.4 hours of strong sunshine.

The mean monthly temperature was 9.2 degrees celsius (48.5 Fahrenheit), 1.3 C warmer than the long-term (1796–2010) April average at Armagh and nearly 0.7 C warmer than the most recent (1981–2010) 30-year April average.

This was the warmest April at Armagh for three years, that is, since April 2014 (mean temperature 10.5 C).

The warmest day (highest maximum air temperature) was 17.1 C on the 30th, and the warmest night (highest minimum air temperature) was 9.3 C on the 20th.

The coolest day (lowest maximum air temperature) was 10.2 C on the 24th, and the coolest night (lowest minimum air temperature) was -0.6 C on the 26th.

There were several quite sharp ground frosts among the 11 nights during which the minimum grass temperature fell below zero celsius, the coldest of which were those on the 26th and 25th (minimum grass temperatures of -8.4 C and -5.9 C respectively).

Snow pellets and hail were noted on the afternoon of the 25th.

The first swallow was seen on the 20th, and a rainbow noted during early evening on the 14th.

There was just one night, the 26th, with a nighttime air frost (minimum air temperature less than zero celsius).

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