Sign In Become a Member
Donate
Daily Discussions

Tuesday, May 13, 2025

May 13, 2025

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA TUESDAY, MAY 13, 2025 ALL TIMES ARE…

Agreement required — click “Accept & Continue” below to review and accept the Data Use & Privacy Policy

Access to this content requires acceptance of our Data Use & Privacy Policy.

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

TUESDAY, MAY 13, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0425E
SUNSET:  1857E

COMFORTABLE TEMPERATURES ONCE AGAIN WITH FILTERED SUNSHINE….

Today has featured plenty of sunshine, albeit filtered through
thin cirrus clouds. Somewhat thicker cirrostratus clouds have
been observed to the distant south through west, but for now
they haven’t made much progress toward the area. The high pollen
count is once again the only negative of the day which is reducing
visibility a bit as seen by increased haziness.

Temperatures are slightly above seasonal levels for this time of
year with readings in the upper 60s to 70F. Dew point values
are starting to rise a bit, from the upper 30s this morning to the
mid 40s by early this afternoon. However, it’s still a very
comfortable air mass in place.

Winds have been fairly steady most of the day out of an easterly
direction. The average speed for the day so far is around 10mph.
There have been occasional gusts over 20mph, but they have been
rather infrequent. The peak gust so far is 26mph, which occurred
just before 10am this morning.

Visibility has been decent, although it has decreased a bit as
mentioned above due to the increase in pollen in the air. The view
started the day around 60 miles, but has slipped to around 45-50
miles by early this afternoon.

The maximum temperature for today is 70F degrees, which is 4 degrees
above the normal high of 66F. The minimum temperature since midnight
is 56F degrees, which is 9 degrees above the normal low of 47F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Thin broken cirrus
Temperature: 61F; Dew Point: 40F; Relative Humidity: 46%
Wind: ESE @ 10G16 kts
Sea-level pressure: 1025.6 mb; 30.29 in. Hg: rising, then more rapidly
Visibility: 60 miles
6-hr Max temp: 61F
6-hr Min temp: 56F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E250 -BKN 60 256/61/40/1110G16/029/ 8/001 53022 10061 20056

10 A.M.
Weather: Thin broken cirrus, few cirrostratus distant SSW-W
Temperature: 68F; Dew Point: 38F; Relative Humidity: 33%
Wind: SE @ 10G23 kts
Sea-level pressure: 1026.4 mb; 30.31 in. Hg: rising, then more slowly
Visibility: 50 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E250 -BKN 50 264/68/38/1310G23/031/ FEW CS DSNT SSW-W/
8/005 51008

1 P.M.
Weather: Thin broken cirrus
Temperature: 67F Dew Point: 46F; Relative Humidity: 48%
Wind: NE @ 8G16 kts
Sea-level pressure: 1025.8 mb; 30.29 in. Hg: falling, then more rapidly
Visibility: 50 miles
6-hr Max temp: 70F
6-hr Min temp: 61F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E250 -BKN 50 258/67/46/0508G16/029/ 8/001 58006 10070 20061

————————————————————–

SUMMARY FOR MONDAY, MAY 12, 2025

TEMPERATURE (DEGREES F)
MAX…….73   NORMAL…..66
MIN…….46   NORMAL…..47
MEAN……60   NORMAL…..57

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+3
TOTAL DEPARTURE FOR THE MONTH………………………+44 [+3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………..5  DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE MONTH…………….80  DEPARTURE…….-46
TOTAL HEATING UNITS FOR THE SEASON………….5478  DEPARTURE……-535
TOTAL HEATING UNITS LAST SEASON TO DATE……..5301  DEPARTURE……+177

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH……………..4  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE SEASON…………….7  DEPARTURE……..-1
TOTAL COOLING UNITS LAST SEASON TO DATE………..2  DEPARTURE……..+5

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated

F420C (Official)………..36 SW   @   03:41 P.M.
VECTOR #1 (1-Sec)……….34 SW   @   02:21 P.M.
VECTOR #2 (1-Sec)……….36 SW   @   02:21 P.M.
DAVIS #1……………….36 S    @   01:13 P.M.
DAVIS #2 ………………33 S    @   09:30 A.M.
RMY #1 (Instantaneous)…..36 SW   @   03:40 P.M.
RMY #2 (Instantaneous)…..37 SW   @   02:21 P.M.
MERLIN…………………33 SW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 SW   @   03:30 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..23      @   03:30 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..25      @   03:30 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 SW   @   03:30 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………25 WSW  @   03:29 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..23 SW   @   03:30 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..25 SW   @   03:30 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.0 SW [312 total miles] VECTOR #1………………13.1
VECTOR #2………………13.6
DAVIS #1……………….12.9 SW
DAVIS #2……………….13.7 SW
RMY #1…………………12.8 SW
RMY #2…………………13.6 SW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.11
TOTAL PRECIPITATION FOR THE MONTH…………..2.72 DEPARTURE…..+1.27
TOTAL PRECIPITATION FOR THE YEAR (2025)…….16.84 DEPARTURE…..-3.39

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.8 DEPARTURE…..-33.9

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY:  R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

5/1   69/43/56/+3/0.00/0.0/744/88        28 S   VEC1 28 SSW RMY 28
5/2   79/47/63/+9/0.19/0.0/339/40        28 SE  VEC1 29 SE  RMY 25 TSTM
5/3   84/54/69/+15/0.15/0.0/561/66       43 SSW VEC1 42 SSW RMY 44 TSTM
5/4   77/50/64/+10/0.06/0.0/256/30       33 SW  VEC1 34 SW  RMY 32
5/5   50/46/48/-7/0.26/0.0/000/00        35 ENE VEC1 35 ENE RMY 36
5/6   61/48/55/0/0.57/0.0/000/00         26 S   VEC1 27 ENE RMY 27
5/7   72/54/63/+8/0.01/0.0/310/36        33 SSW VEC1 33 SW  RMY 35
5/8   74/51/63/+8/0.04/0.0/…/..        18 ESE VEC1 18 ESE RMY 18
5/9   51/46/49/-7/1.15/0.0/…/..        33 E   VEC1 34 ENE RMY 35
5/10  62/45/54/-2/0.29/0.0/…/..        36 NW  VEC1 37 NW  RMY 41
5/11  70/49/60/+4/0.00/0.0/…/..        33 NW  VEC1 32 NW  RMY 34
5/12  73/46/60/+3/0.00/0.0/…/..        36 SW  VEC1 34 SW  RMY 36

5/13 The low since midnight is 56F, the daily normal low is 47F.

————————————————————–

MAY DAILY RECORDS TO DATE

NONE.

————————————————————–

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR MAY 13
HIGH 85F IN 1947
LOW 32F IN 2020
PRECIP 2.39 INCHES IN 2006
PEAK GUST 49 MPH NNW IN 1965

RECORDS FOR MAY 14
HIGH 85F IN 1961,2022
LOW 33F IN 1895
PRECIP 1.93 INCHES IN 2006
PEAK GUST 53 MPH S IN 2009

TODAY’S REPORT PREPARED BY: MFD

facebookShare on Facebook
TwitterPost on X
FollowFollow us
PinterestSave
←
→
Blue Hill Observatory & Science Center · Legal

Data Use & Privacy Policy

Please read the full Policy before accessing Observatory data · Effective January 1, 2025

Notice: By accessing, downloading, or using any Blue Hill Observatory data or services, you unconditionally accept and agree to be bound by this Policy in its entirety. If you do not agree, you may not access or use Observatory data.
Effective January 1, 2025 · Milton, Massachusetts · bluehill.org
Part I — Data Use Policy
§ 01

Ownership and Proprietary Rights

All observational records, compiled datasets, metadata, database structures, and related materials provided by the Blue Hill Observatory & Science Center are the exclusive property of the Blue Hill Observatory & Science Center. The Observatory has maintained continuous weather observations at the summit of Great Blue Hill since 1885, and the entirety of that record — its compilation, structure, curation, and organization — constitutes a proprietary database protected under applicable United States law, including copyright law and common law database protections.

All rights not expressly granted in this Policy are reserved by the Observatory. No access to or use of Observatory data shall be construed as a waiver of any rights or as a license to use data beyond the scope expressly stated herein.

§ 02

Governing Law and Jurisdiction

This Policy shall be governed by and construed in accordance with the laws of the Commonwealth of Massachusetts, without regard to its conflict of law provisions. For interactions with international users, this Policy shall apply to the maximum extent permitted by applicable local law.

Any dispute arising from or related to this Policy shall be subject to the exclusive jurisdiction of the state and federal courts located in Norfolk County, Massachusetts. By accessing Observatory data, all users consent to personal jurisdiction in Massachusetts and waive any objection to the venue or inconvenience of such forum.

§ 03

Permitted Uses

Observatory data are made available for the following limited, non-commercial purposes only:

  • Personal study and analysis
  • Educational classroom use
  • Student projects
  • Non-commercial academic research
  • Publication of analyses, figures, models, or conclusions derived from the data, subject to the attribution requirements of Section 4

All other uses require prior written authorization from the Observatory.

§ 04

Attribution Requirement

Any use of Observatory data in any published, presented, or publicly distributed work must include the following verbatim acknowledgment:

“Data provided by the Blue Hill Observatory & Science Center, Milton, Massachusetts. Continuous weather observations since 1885.”

Failure to include proper attribution is a material violation of this Policy.

§ 05

Prohibited Uses

Unless explicitly authorized in writing, Users may not:

  • Resell, license, sublicense, or commercially exploit Observatory data in any form
  • Redistribute the dataset in whole or in part to any third party
  • Publish the dataset for download by third parties
  • Host, mirror, or archive the dataset on any external website, repository, or storage service
  • Upload the dataset to any public or institutional data repository
  • Provide the data through APIs, automated services, or subscription platforms
  • Incorporate the data into any commercial product, software, application, or service
  • Use the data for AI or machine learning systems intended for commercial use or external distribution
  • Use the data to create derivative datasets that enable reconstruction of the underlying observations
§ 06

Commercial Licensing

Organizations seeking to use Observatory data for commercial purposes must obtain a license prior to any such use. Licensing inquiries: data@bluehill.org.

§ 07

Automated Access

Automated scraping, bulk harvesting, or systematic downloading of Observatory data is strictly prohibited without prior written authorization.

§ 08

Enforcement and Remedies

Violation of this Policy may result in immediate revocation of data access, pursuit of legal remedies available under United States law, and referral to applicable authorities. The Observatory reserves all rights to seek injunctive relief, damages, and attorneys’ fees in connection with any unauthorized use of its data.

Part II — Privacy Policy
§ 09–10

Scope & Information Collected

This section governs the collection, use, storage, and disclosure of personal information from visitors to the Blue Hill Observatory website and users of its data services. The Observatory may collect contact information (name, email, organization) when voluntarily submitted, usage data including IP addresses and pages visited, and data download records.

§ 11–12

How We Use Information & Retention

Information is used solely for: responding to inquiries and licensing requests; monitoring and enforcing compliance with this Policy; improving website performance; and communicating Observatory news to opted-in users. The Observatory does not sell, rent, or share personal information with third parties for marketing purposes. Data access records may be retained indefinitely for compliance and enforcement purposes.

§ 13

International Users and Data Transfers

The Observatory is located in the United States. International users acknowledge their information will be processed in the United States under U.S. law. Users requiring specific data processing agreements under non-US law must contact data@bluehill.org before accessing data.

§ 14–16

Cookies, Security & Children’s Privacy

The Observatory website may use cookies for analytics and functionality. By continuing to use the site, users consent to cookie use. The Observatory implements reasonable measures to protect personal information but cannot guarantee absolute security. Observatory data services are not directed at children under 13.

Part III — General Provisions
§ 17–20

Modifications, Severability, Entire Agreement & Contact

The Observatory reserves the right to modify this Policy at any time. Updated versions will be posted at bluehill.org. Continued use of Observatory data following any modification constitutes acceptance of the revised Policy. This Policy constitutes the entire agreement between the User and the Observatory. Questions and licensing inquiries: Blue Hill Observatory & Science Center, Milton, Massachusetts — data@bluehill.org

By accessing, downloading, or using any Blue Hill Observatory data or services, you acknowledge that you have read, understood, and agree to be bound by this Policy.
Effective January 1, 2025 · Blue Hill Observatory & Science Center · Milton, Massachusetts
↓ Scroll to read the full Policy — the agreement checkbox will unlock at the bottom
Main Menu