Sign In Become a Member
Donate
Daily Discussions

Sunday, May 17, 2026

May 17, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SUNDAY, MAY 17, 2026 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

SUNDAY, MAY 17, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0421E
SUNSET:  1901E

A TASTE OF SUMMER WITH VERY WARM TEMPERATURES UNDER A SUNNY SKY….

High pressure continues to be anchored near Bermuda with another
area of high pressure over central Ontario. Aloft a ridge is
gradually building northeastward into the region.

This is all allowing for what can only be described as a spectacular
stretch of weather. Sunshine has been abundant again today with a
westerly breeze and very warm temperatures. It’s been a perfect
day for any and all outdoor activities.

Temperatures have warmed markedly today into the mid 80s, which is
almost 20 degrees above normal for the date. A real taste of
summer! The one saving grace is that dew point values are still
in the comfortable range with readings in the mid to upper 50s,
which is perfect!

Winds were steady overnight and then diminished in speed during
the morning hours. However, they are picking up once again as we
move into the afternoon hours as mixing from aloft begins. The
wind has generally been westerly through the day averaging at
around 12mph for the day so far. The peak gust so far for the day
is 39mph, which occurred during the 1pm observation period.

Visibility has been limited today due to haziness, likely mostly
from the high pollen count. The view has been stuck at around
35 miles all day.

The maximum temperature so far today is 85F degrees, which is
18 degrees above the normal high of 67F. The minimum temperature
since midnight is 56F degrees, which is 7 degrees above the
normal low of 49F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken cirrus
Temperature: 64F; Dew Point: 58F; Relative Humidity: 80%
Wind: W @ 8 kts
Sea-level pressure: 1015.2 mb; 29.98 in. Hg: rising unsteadily
Visibility: 35 miles, hazy
6-hr Max temp: 64F
6-hr Min temp: 56F
24-hr Precip: 0.05 inches
BHO SA 1155 E250 BKN 35 152/64/58/2708/998/ HAZY/ 8/001 52016
6003/ 70005 10064 20056

10 A.M.
Weather: Clear, few cirrus distant ESE-SSW
Temperature: 77F; Dew Point: 54F; Relative Humidity: 45%
Wind: W @ 8G17 kts
Sea-level pressure: 1016.7 mb; 30.02 in. Hg: rising, then more rapidly
Visibility: 35 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 35 167/77/54/2808G17/002/ FEW CI DSNT ESE-SSW
HAZY/ 8/001 53015

1 P.M.
Weather: Scattered cumulus
Temperature: 85F; Dew Point: 56F; Relative Humidity: 37%
Wind: W @ 19G34 kts, peak wind W 39mph at 12:50 P.M.
Sea-level pressure: 1016.0 mb; 30.00 in. Hg: falling, then more rapidly
Visibility: 35 miles, hazy
6-hr Max temp: 85F
6-hr Min temp: 64F
6-hr Precip: 0.00 inches
BHO SA 1755 40 SCT 35 160/85/56/2819G34/000/ HAZY PK WND 2834/50/
8/200 58007 10085 20064

————————————————————–

SUMMARY FOR SATURDAY, MAY 16, 2026

TEMPERATURE (DEGREES F)
MAX…….78   NORMAL…..67
MIN…….47   NORMAL…..48
MEAN……63   NORMAL…..58

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+5
TOTAL DEPARTURE FOR THE MONTH……………………….-4 [-0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..2  DEPARTURE……..-6
TOTAL HEATING UNITS FOR THE MONTH (MAY)………155  DEPARTURE……..-5
TOTAL HEATING UNITS FOR THE SEASON………….5991  DEPARTURE…….-56
TOTAL HEATING UNITS LAST SEASON TO DATE……..5486  DEPARTURE……+505

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH (MAY)………..0  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON…………….6  DEPARTURE……..-5
TOTAL COOLING UNITS LAST SEASON TO DATE……….12  DEPARTURE……..-6

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 *=Last of multiple occurrences

F420C (Official)………..33 SW   @   05:48 P.M.
VECTOR #1 (1-Sec)……….34 SSW  @   05:46 P.M.
VECTOR #2 (1-Sec)……….33 SW   @   06:29 P.M.
DAVIS #1……………….32 SW   @   05:46 P.M.
DAVIS #2 ………………32 W    @   02:34 P.M.
RMY #1 (Instantaneous)…..35 SSW  @   05:46 P.M.
RMY #2 (Instantaneous)…..34 SSW  @   06:28 P.M.
MERLIN…………………32 SW
RICHARDS (C5C) (Inst)……32 SW   @   05:55 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………23 SW   @   05:54 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22 SW   @   06:12 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24 SSW  @   05:49 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 SW   @   02:36 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 SW   @   05:49 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 SSW  @   05:47 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..24 SSW  @   05:49 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………22 SW   @   02:36 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.5 WSW [324 total miles] VECTOR #1………………13.4
VECTOR #2………………14.0
DAVIS #1……………….13.4 SW
DAVIS #2……………….13.5 WSW
RMY #1…………………13.3 WSW
RMY #2…………………13.9 SW
RICHARDS (C5C)………….12.8

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.05 DEPARTURE…..-0.06
TOTAL PRECIPITATION FOR THE MONTH (MAY)……..1.04 DEPARTURE…..-0.87
TOTAL PRECIPITATION FOR THE YEAR (2026)…….14.71 DEPARTURE…..-5.98

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE MONTH (MAY)…………..0.0 DEPARTURE……0.0
TOTAL SNOWFALL FOR THE SEASON (2025-2026)……81.6 DEPARTURE….+11.9

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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  63/43/53/0/0.00/769/91              26 WNW VEC1 27 NNW RMY 27
5/2  58/45/52/-2/0.04/127/15             29 SSW VEC1 29 SSW RMY 28
5/3  53/41/47/-7/T/119/14                37 NW  VEC1 36 NW  RMY 39
5/4  71/41/56/+2/0.00/775/91             46 SW  VEC1 46 SW  RMY 48
5/5  78/49/64/+9/0.00/718/84             43 SSW VEC1 43 SSW RMY 45
5/6  68/54/61/+6/0.08/146/17             43 SSW VEC1 42 SSW RMY 44
5/7  65/46/56/+1/0.22/697/81             28 WNW VEC1 27 WNW RMY 28
5/8  62/40/51/-4/0.00/741/86             33 W   VEC1 33 W   RMY 33
5/9  58/43/51/-5/0.35/000/00             30 SSW VEC1 31 SSW RMY 30
5/10 72/49/61/+5/T/346/40                28 SSW VEC1 28 SSW RMY 27
5/11 62/45/54/-2/T/191/22                26 NNW VEC1 26 NNW RMY 26
5/12 63/42/53/-4/T/835/96                29 WNW VEC1 29 WNW RMY 29
5/13 65/46/56/-1/T/122/14                41 S   VEC1 40 S   RMY 44
5/14 61/48/55/-2/0.26/…/..             37 SSE VEC1 38 SE  RMY 36
5/15 56/47/52/-5/0.04/…/..             18 NE  VEC1 19 NE  RMY 20
5/16 78/47/63/+5/0.00/…/..             33 SW  VEC1 34 SSW RMY 35

5/17 The low since midnight is 56F, the daily normal low is 49F.

————————————————————–

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 17
HIGH 90F IN 2017
LOW 34F IN 1956, 1957
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974

RECORDS FOR MAY 18
HIGH 96F IN 2017(RECORD FOR MAY)
LOW 35F IN 2002
PRECIP 1.93 INS IN 2007
SNOW TRACE IN 2002 (Ice pellets)
PEAK GUST 64 MPH SSW IN 2000

TODAY’S REPORT PREPARED BY: Matt Douglas

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