Gaithersburg 2 WNW Maryland – weather summary for NJWO Blog and Weathershelter


Average high temperature 66.5° (+ 0.3°)
Average low temperature 43.4° (+ 1.7°)
Mean temperature 54.9° (+ 0.9°)
Precipitation 1.79″ (- 1.87″) Greatest daily amount (date) 0.81″ (7)
Year to date precipitation 12.76″ (- 0.92″)
Snowfall T (- 0.4″) Greatest daily amount (date) T (9)
Greatest depth of snow (date) T (9)
Seasonal snowfall (2015-2016) 37.9″ (+9.1″)
High temperature for the month (date) 84° (18)
Low temperature for the month (date) 27° (6)
Highest barometric pressure (date) 30.51″ (17)
Lowest barometric pressure (date) 29.40″ (2)
Peak wind gust (date/direction): 32 (3/WSW) Heating degree days for the month: 320
Cooling degree days for the month: 18
Greatest diurnal range (date): 38.4° (18) Least diurnal range (date) 7.2° (30)

Fog days: 4
Snow days: 1
Glaze: 0
Thunder: 0
Sunny/clear days: 13 Partly Cloudy days: 10 Cloudy days: 7

Days with measurable precipitation (=>.01″) = 10
Days with maximum temperatures of 80 or more = 5
Days with minimum temperatures of 32 or less = 3

by Kevin Shaw, observer in charge

April 2016 was a dry, slightly warmer than normal month with much more of an emphasis on the low precipitation total rather than the temperatures. There has been a lack of dry Aprils in my 37 period of record (POR), so this modestly dry month is
now coming in as my third driest April since 1979 when my
records for April start. Naturally no daily precipitation
record amounts were set, as the wettest day of 0.81″ on the
7th didn’t come close to the all-time daily record for that
date. Even though temperatures were pretty close to normal,
there were a few extremes that set daily records. The 83°
on the 1st set the only daily record high temperature for the date, and there were two record high minimum temperature
records set, the 2 warmest low temps for the month, both
in the 60s that beat the old record significantly. 64° was
the low temperature on the 1st and the 22nd that set daily
record high minimum temperatures. There were 5 days with
maximum temperatures of 80° or greater, and 3 days with
minimum temperatures below freezing. Both values are pretty
close to average I believe, though I don’t really compile a
statistic for the 80° max. Snow did fall (a trace) on the 9th which is the 22nd April out of 37 to have at least a trace.

The average maximum temperature for the month was 66.5°
(+0.3°), the average minimum temperature was 43.4° (+ 1.7°). The resultant mean average temperature for the month was
54.9° (+ 0.9°). It was not nearly as warm a month when
compared to March in relation to to the long-term averages.

The month’s total precipitation amount of 1.79″ was 1.87″
below the normal April amount of 3.66″. Precipitation was
spread out on 10 of the 30 days of April, with a 10 day period of no rain (13th-22nd). Most of the month’s rain fell on the first 12 days and the last few days of the month. Speaking of streaks, those last 3 days of the month kicked off a streak of daily rain that is still intact through May 9. More on that with the May report. 10 days of measurable precipitation for the
month was a bit below the long-term normal amount of 11.3 days. Total snowfall for the month of a trace was 0.4″ below the long term April average of 0.4″.

The month’s highest barometric pressure reading of 30.51″ on the 17th occurred near the beginning of the 10 day dry spell which also brought on 70s and 80s high temperatures. The lowest pressure reading of the month was 29.40″ on the 2nd occurred during a colder, damper period with light precipitation amounts that featured our highest peak winds gusts of the month.

The distribution of 13 sunny, 10 partly cloudy and 7 cloudy days fit in the dry pattern a bit better than in March. The sunny days naturally mostly occurred during that 10 day dry, warm streak between the 13th and 22nd.

There were 320 heating degree days (HDD) and 18 cooling degree days. There were an about normal amount of 4 days with fog with no other special observation phenomena noted. The peak wind gust during the month was 32 MPH out of the WSW on the 3rd, behind a strong frontal passage in the middle of the windiest period of the month, with 4 of the month’s 8 PWG values over 20 MPH and the top three during the first 4 days of the month.

My maximum temperature frequencies included 5 days of 80° or more, 9 days between 70° and 79°, 7 days between 60° and 69°, 7 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 20° and 29°, 8 days between 30° and 39°, 12 days between 40° and 49°, 5 days with minimums between 50° and 59°, and 2 days with minimums of 60° or greater.

The diurnal range average was a bit below normal (23.1° vs the normal of 24.6°). The max daily range of 38.4° occurred on the 18th in the middle of our 10 day dry streak and the peak of the greatest hot spell of the month when the monthly max temp was reached (84°- 46°). There were an additional 7 days with daily ranges in the 30° – 39° range. The lowest daily temperature range of 7.2° occurred on the 30th near the beginning of our consecutive wet day period still currently running. There was a total of 4 days during April with daily temperature ranges of less than 10°.

April 2016 wound up a fairly typical transitional month from some winter-like conditions at the beginning of the month to more summer-like conditions near the end. Springtime green-up and tree blossom season was pretty close to normal this year. But there was a notable lack of convective activity in April, but that has picked up a bit in early May so far. Stay tuned in a few weeks for the May report. We have started out wet and cool so far in early May. For my own personal preference considerations, I hope we can maintain that pattern for as long as possible to keep us out of the heat and humidity that is inevitable eventually during the coming weeks.

This email has been checked for viruses by Avast antivirus software.

This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s