BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, JUNE 1, 2009   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A VERY COOL START TO JUNE THIS MORNING
BUT TEMPERATURES WARM QUICKLY TO THE 60'S
UNDER A SUNNY SKY AND SOUTHWEST WINDS
 
After a pleasantly warm, rather windy
day yesterday a brief rain shower with
a few rumbles of thunder preceded the
passage of a cold front last evening.
Winds, which gusted just of 40 MPH from
the south during the afternoon shifted
to west with gusts again just over 40 MPH.
during last evening.
Temperatures fell rapidly from an after-
noon high of 77F to 46F by midnight and
then on down to 41F around sunrise this
morning.  This low reading equaled the
lowest temperature for all of May, fell
11 degrees below normal for 1 June and
came within 5 degrees of the minimum
for any date in June. The lowest for any
date in June being 36F on June 1, 1945.  
 
THE MAY 2009 STATS
Temps. Deg. F
Av. Max. 67.5
Av. Min. 48.8
Mean     58.2 [+1.2]
24-hour corr. mean: 57.8
Max. temp: 89, 21st
Min. temp: 41, 11th
Total heating units: 225 [-46]
Total this season:  6121 [-176] 
Total cooling units:  21 [ 0  ]
Total this season:    39 [+14 ]
Av. vapor pressure: 11.4 mbs.
Precipitation [inches]
Total for the month: 3.89 [+0.10]
Greatest in 24 hours: 1.35 [5-6th]
[trace of hail, 24th]
Number of days measurable precip: 15
Total number of days with precip: 19
Total for 2009 to date: 18.50 [-3.24]
Wind [miles per hour]
Av. speed: 11.6
Av. speed (corr.) 12.1
Prevailing direction: S @ 15%
Peak gust: 53 S on 14th,
and W on 10th
Fastest mile: 38 W on 10th
Sunshine data: astronomical, 12708/27136 mins. or 47%
Uncorrected (card minutes) 12264 (204.4 hours)/26226,
also 47%
 
Today's observations:
 
7 A.M.  
Weather: Thin broken cirrus, few altocumulus and altocumulus
lenticularis distant west thru north thru east 
Temperature: 49F, Dew point: 32F, Wind: W at 7 kts
Sea-level pressure: 30.08 inches Hg, rising
Visibility: 70 miles, 80 miles northwest
6-hour minimum temp: 41F  
24-hour rainfall: 0.03 inch
BHO SA 1155 250 –SCT 300 –BKN 70 185/49/32/2607/008/
PTCHS AC/FEW ACSL DSNT W-N-E VSBY NW 80/ 8/041 53018
ASOS 70002 MANUAL 70003 10049 20041 
 
10 A.M.  
Weather: Clear, few altocumulus and cirrus distant
northwest through north 
Temperature: 57F, Dew point: 36F, Wind: SW at 9 kts,
Wind: Direction variability south thru west-southwest
Sea-level pressure: 30.08 inches Hg, rising slightly
Visibility: 75 miles
BHO SA 1455 CLR 75 186/57/36/2309/008/
FEW AC/CI DSNT NW-N WND 17V25/ 8/041 53001
 
1 P.M.  
Weather: Clear, altoumulus distant southwest through north
through north-northeast, cirrus distant west to northwest  
Temperature: 66F, Dew point: 38F, Wind: SSW at 11G22 kts,
Wind: Direction variability SSE to WSW
Sea-level pressure: 30.05 inches Hg, falling
Visibility: 75 miles
6-hour maximum temp: 67F
BHO SA 1755 CLR 75 175/66/38/2111G22/005/
AC DSNT SW-N-NNE CI DSNT WSW-NW WND 16V25/
8/041 56011 10067 20049
 
WEATHER SUMMARY FOR SUNDAY, MAY 31
 
TEMPERATURE (DEGREES F)
MAX.....77    NORMAL.....72
MIN.....46    NORMAL.....52
MEAN....62    NORMAL.....62
 
DEPARTURE FROM 30-YEAR NORMAL............0
TOTAL DEPARTURE FOR THE MONTH..........+44 [+1.2 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............3  DEPARTURE.......-2
TOTAL HEATING UNITS FOR THE MONTH...........225  DEPARTURE......-46
TOTAL HEATING UNITS FOR THE SEASON.........6121  DEPARTURE.....-176
TOTAL HEATING UNITS LAST SEASON TO DATE....5901  DIFFERENCE....+220
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............42 W   AT 8:15 P.M.
                   AEROVANE..............42 W   AT 1:47 P.M. *
                   ASOS..................41 W   AT 8:15 P.M.    
                   DAVIS.................43 SSW AT 2:43 P.M.  
FASTEST MILE FOR YESTERDAY...............29 W   AT 8:17 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............30 S   AT 2:44 P.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE...........31 SSW AT 2:44 P.M.   
AVERAGE WIND SPEED AND DIRECTION........15.1 S 
                   ASOS.................14.2
                   DAVIS................14.0 SW  [230 DEG]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.03  DEPARTURE....-0.10
                         ASOS..............0.02
TOTAL PRECIPITATION FOR MAY................3.89  DEPARTURE....+0.10
                         ASOS..............3.87 
TOTAL PRECIPITATION FOR THE YEAR..........18.50  DEPARTURE....-3.24
                         ASOS.............19.55 
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1  64/53/59/+7/T/000/00          37 SSW   AERO 37 MPH SSW
5/2  68/52/60/+8/0.05/263/31       32 WNW
5/3  64/48/56/+3/T/068/08          25 S
5/4  64/48/56/+3/0.01/009/01       17 SSW
5/5  52/44/48/-5/0.95/000/00       43 NNE   AERO 40 MPH NNE
5/6  63/43/53/-1/0.40/189/22       24 SSE  
5/7  68/49/59/+5/0.60/009/01       29 S     
5/8  75/52/64/+10/0/690/80         28 S
5/9  71/55/63/+8/0.14/104/12       31 W     TSTM
5/10 65/46/56/+1/0/840/97          53 W     Aero 50 MPH W
5/11 63/41/52/-3/0/781/90          24 WNW
5/12 63/45/54/-2/0/696/80          22 ENE
5/13 70/45/58/+2/0/732/84          31 SSE   AERO 29 MPH SSE
5/14 62/47/55/-2/0.10/166/19       53 S     AERO 52 MPH S
5/15 76/54/65/+8/0/474/54          38 S     AERO 38 MPH S
5/16 68/54/61/+4/T/457/52          35 S     AERO 35 MPH S
5/17 61/49/55/-2/0.09/009/01       35 WNW   AERO 33 MPH WNW
5/18 53/42/48/-10/0.04/168/19      27 NE   
5/19 70/42/56/-2/0/813/92          28 S 
5/20 82/49/66/+8/0/771/87          31 SSW
5/21 89/59/74/+15/0/870/98         37 S     AERO 34 MPH S
5/22 87/59/73/+14/0/739/83         31 N
5/23 65/50/58/-1/T/428/48          28 NE
5/24 80/50/65/+5/1.07/536/60       25 WNW   TSTM TRACE DIME SIZE HAIL
5/25 76/51/64/+4/0/868/97          32 N 
5/26 58/46/52/-8/0/601/67          28 NNE
5/27 52/43/48/-13/0.16/000/00      23 E    
5/28 48/45/47/-14/0.03/000/00      28 NE    AERO 25 MPH NNE
5/29 63/48/56/-5/../000/00         17 NE
5/30 76/59/68/+7/../713/79         32 WSW  
5/31 77/46/62/0/0.03/714/79        42 W     AERO 42 MPH W TSTM
 
6/1  our morning low temp: 41F; the normal low is now 52F
 
NEW DAILY RECORDS FOR MAY 2009...
5/14: RECORD PEAK WIND GUST 53 MPH S;
      surpasses previous record of 50 MPH SW in 1976
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR JUNE 1
HIGH 90F IN 1937
LOW 36F IN 1945 [Record for month]
PRECIP 2.28 INS IN 1992
PEAK GUST 51e MPH SE IN 1952
 
RECORDS FOR JUNE 2
HIGH 91F IN 1895
LOW 41F IN 1907, 1929
PRECIP 2.36 INS IN 1982
PEAK GUST 63 MPH NW IN 2000
 
TODAY'S REPORT PREPARED BY: Robert Skilling