APRIL 2019 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
by Kevin Shaw, Observer
April 2019 was drier and warmer than normal. My max temp (68.8°) was 3.5° above normal
and my min temp (49.7°) was even more significantly 6.8° above normal, resulting in the
mean temperature (59.3°) to be 5.2° above normal. My total precipitation of 2.36″ was
0.93” below the newly computed normal precipitation April value for my station of 3.29”.
There was no snowfall recorded, though some northern county areas did record a few
trace flakes on the morning of April 1. There were a lot of smaller amounts of daily
precipitation leading to an above normal 13 days with measurable precipitation. .
There were a few colder than normal days during the first few days of the month which
included the only day with a freezing min (30.2° on the 1st) during all of April. The rest
of the month had seasonable to seasonably warm temperatures, but nothing summerlike
as above 80° was reached only twice during the month. There were 5 days during the
month when mins of 60° or greater were reached however.
There were 13 days with measurable precipitation, highlighted by the monthly maximum
of 0.67″ on the 26th helped by a strong mid-afternoon thunderstorm accompanied by
my monthly lowest pressure reading of 29.36”. The wettest storm period of the month
was on the 25th-26th when a total of 0.71” was recorded. Precipitation was spread
fairly evenly throughout the month with only two modest 4 day streaks of no rain on
the 1st-4th and 21st-24th. The highest barometric pressure reading of the month of
30.46” occurred on the 29th. There were no really notable precipitation days during
the month as all days with measurable precipitation were well under a half an inch daily
except of course for the rainiest day on the 26th as already noted. .
The highest dew point temperature reached during the month was 68° on the 19th.
There were 11 days in April when dew point temps were 60° or higher, values I consider
humid for April. My warmest air temperature of the month (80.8°) was recorded a few
days later on the 23rd. The lowest dew point temperature value was reached on the 1st
(coldest day of the month) when a value of 15° was reached.
April had 12 cloudy days, 16 partly cloudy days, and only 2 really clear/sunny days.
There were 196 heating degree days and 23 cooling degree days during the month.
There were 5 foggy days, 2 windy days, and 3 days with thunder during April.
Daily max/min temperatures varied as they usually do during the spring. My maximum
temperature frequencies included 2 days over 80°, 14 days between 70° and 79°, 10
days between 60° and 69°, 2 days between 50° and 59°, and 2 days between 40° and
49°. On the minimum temperature frequency side of things, there were 3 days
between 30° and 39°, 11 days between 40° and 49°, 11 days between 50° and 59° and
5 days above 60°. The coldest daily max temperature was 46.3° on the 1st while the
warmest daily min temp of 64.6° was on the 19th.
The diurnal range daily monthly average was 19.1° (- 3.3°). Our greatest daily range of
temperature was 33.0° on the 3rd, formed from a high of 66.4° and the low of 33.4°.
We had a total of 5 days with daily ranges above 25.0°. Our lowest range of
temperature was 9.0° (73.6°-64.6°) on the 19th during our highest dew point and
warmest min values of the month. There were 8 total days with diurnal temperature
ranges of less than 15.0° throughout the month, spread out fairly evenly..
April 2019 was a typical transitional month from winter to spring, with patterns during
the month generally filling the bill quite well. No problems were experienced with my
weather station during the month thank goodness. I recovered all of the winter snow-
measuring devices during the month, and broke out my lightning detector.
APRIL 2019 – ROCKVILLE 2.8 WNW MARYLAND – SUMMARY STATISTICS
Average high temperature 68.8° (+ 3.5°)
Average low temperature 49.7° (+ 6.8°)
Mean temperature 59.3° (+ 5.2°)
Precipitation 2.36″ (- 0.93”)
Greatest daily amount (date) 0.67″ (26)
Greatest storm total (dates) 0.71” (25-26)
2019 year-to-date precipitation total 14.39″ (+1.70”)
Seasonal snowfall total (final) 26.8″
High temperature for the month (date) 80.8° (23)
Low temperature for the month (date) 30.2° (1)
Highest barometric pressure (date) 30.46” (29)
Lowest barometric pressure (date) 29.36” (26)
Peak wind gust (date/direction): N/A
Heating degree days for the month: 196
Cooling degree days for the month: 23
Greatest diurnal range (date): 33.0° (3)
Least diurnal range (date) 9.0°(19)
Number of days:
Partly Cloudy 16
Max temp ≥ 70° 16
Max temp =< 32° 0
Min temp =< 32° 1
Precip ≥ 0.01” 13