AUGUST 2018 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
By Kevin Shaw, Observer in ChargeAugust 2018 was similar in many respects to July. Temperature averages were just about the same,
and both July and August were wet months. In fact, the wettest day of each month both fell on the
21st of the month (4.02” on 7/21, 3.92” on 8/21). August had 6 days with max temps of 90° or
greater and July had 8, but August didn’t have the 5 days in a row heat wave at the beginning of
the month like July did. The biggest difference in temperature issues was minimums of 70° or greater.
July had 11 and August had 21. With global warming, we have been trending to have warmer minimums,
not only in summer but most all months Differences in some patterns between July and August were also
in evidence. The first half of July was very dry, while the first 22 days of August were quite wet.
13 days of measurable rain was pretty close to the normal amount for August and once again compared
favorably with the 12 days in July. It was an incredibly diverse month with Mother Nature turning her
“faucet” on then off.
Once again, significant pressure differences during the month were muted, even more so than in July.
The lack of tropical activity didn’t put a crimp on our rainfall, but didn’t give us very low pressure values
during the month. August’s pressure extremes included the extreme highest pressure for the month
(30.29”) on the 25th with the extreme lowest (29.78”) on the 22nd on the day after our biggest
rain of the month. The month had 10 cloudy days, 13 partly cloudy days, and 8 clear/sunny days.
There were 0 heating degree days and 383 cooling degree days during the month. There were 6 foggy
days and 7 windy days with thunder (mostly all in thunderstorms during our wet periods the first 22
days of the month). The windy day category is subjective with no personal real data values to back it,
just based on my descriptive email daily weather posts that are also posted on weathertogether.net.
Daily max/min temperatures varied about the same as June. My maximum temperature frequencies
included 6 days of 90° or greater, 20 days between 80° and 89°, and 5 days between 70° and 79°.
On the minimum temperature frequency side of things, there was 1 day between 50° and 59.9°,
10 days between 60° and 69.9°, and 20 days at or above 70°. The coolest daily max temperature
was 77.0° on the 23rd with the warmest daily min temp 76.1° on the 16th.
The diurnal range daily monthly average was 15.2°. Our greatest daily range of temperature was
21.9° on the 24th, formed from a high of 80.7° and the monthly low of 58.8°. We had only a
total of 3 days with daily ranges at or above 20°. Our lowest range of temperature was 6.7°
(77.4°-70.7°) on the wettest day of the month on the 21st. There were only 2 other days with
diurnal temperature ranges less than 10.0°, on cloudy, but not particularly wet days.
A recent change to the station was replacing the circuit board for the ISS on my VP2 weather
station, as I had some down time during the month due to system problems. Unfortunately the
development mentioned in my July report of the sprinkler system has persisted in adding
un-natural amounts of water accumulation to my tipping bucket totals in the very early morning
hours. With the coming of fall and winter and the end of the growing season, the sprinklers
should not be running much longer. The cocorahs gauge, located off property in a different
location, does not get this “artificial input” to its official record. I am still constantly checking
on my data quality frequently (which caused me to discover the sprinkler system problem),
along with discussion and data comparison with several of my Maryland weather cohorts.
I continue to occasionally (as time allows) submit GLOBE Cloud observations, complete with
submission of sky pictures at the time of the observation, usually timed with the passage of
satellites and/or solar noon (about 70 minutes past actual EDT noon).
Please ask me any questions you want at any time about my station setup and/or my data
through any means available to you.
AUGUST 2018 – ROCKVILLE 2.8 WNW MARYLAND – SUMMARY STATISTICS
Average high temperature 85.0°
Average low temperature 69.8°
Mean temperature 77.4°
Greatest daily amount (date) 3.92″ (21)
Greatest storm total (dates) 4.06” (21-22)
2018 year-to-date precipitation total 38.08″
High temperature for the month (date) 91.9° (29)
Low temperature for the month (date) 58.8° (24)
Highest barometric pressure (date) 30.29” (25)
Lowest barometric pressure (date) 29.78” (22)
Peak wind gust (date/direction): N/A
Heating degree days for the month: 0
Cooling degree days for the month: 383
Greatest diurnal range (date): 21.9° (24)
Least diurnal range (date) 6.7° (21)
Number of days:
Partly Cloudy 13
Max temp ≥ 90° 6
Min temp < 60° 1
Precip ≥ 0.01” 13 J