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April 2015 Summary – Warmer and Drier Than Average

May 1, 2015

Blue Hill Observatory April 2015 Summary: The month was notable for being generally warmer and drier than average with only a trace…

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Blue Hill Observatory
April 2015 Summary:

The month was notable for being generally warmer and drier than average with only a trace of frozen precipitation. The 24-hour mean temperature for the month of 46.7 deg F was 2.0 degrees warmer than the 120-year average for April, and it was about a half degree warmer than the 1981-2010 30-year average.  The maximum temperature for the month was 69F on the 13th, and the coldest temperature was 26F on the 1st. This was only the twelfth year since 1885 in which the temperature did not reach 70 deg F by the end of April. The last time this occurred was in 1975.  The average minimum temperature for January through April tied for the sixth coldest on record. April was drier than average with a precipitation total of 3.33 inches, which was about an inch less than the 120-year average and the 1981-2010 mean. The monthly snowfall of a trace, which fell as sleet on the 8th, was 2.9 inches less than the long-term average. This kept the seasonal total at 150.8 inches, which is a new seasonal snowfall record. The snow depth on the summit of Great Blue Hill dropped quickly from a high of 8 inches on the 1st to only a trace by the 4th. A residual effect of the cold weather in February and March was the very late thaws of two local ponds. Houghton’s Pond was considered free of ice on April 10th, which tied for the second latest thaw date ever observed, and Ponkapoag Pond was considered thawed on April 11th, which was the latest thaw date on record for that pond in the last 130 years. In a sign of spring, there were two thunderstorm days during the month on the 4th and the 21st, The mean wind speed for the month was 13.0 mph, which was the sixth slowest on record, and the prevailing direction was from the northwest. The peak gust for the month was 54 mph from the northwest on the 4th. April sunshine totaled 199.1 hours, or 51 percent of the possible bright sunshine, which was two percent more than the long-term average.

BHO Lowest Jan-Apr Maximum Temperature, deg F (1885-2015)

1) 66 in 1924
2) 67 in 1893
67 in 1916
67 in 1939
67 in 1966
6) 68 in 1904
68 in 1975
8) 69 in 1917
69 in 1919
69 in 1937
69 in 1971
   69 in 2015

BHO Coldest Jan-Apr Average Minimum Temperature, deg F (1885-2015)

1) 18.9 in 1885
2) 19.3 in 1888
3) 19.7 in 1923
4) 20.0 in 1904
5) 20.5 in 1934
6) 20.9 in 1893
20.9 in 1920
   20.9 in 2015
9) 21.0 in 1887
10) 21.4 in 1907

Latest Houghton’s Pond Thaw Date, (1886-2015)

1) April 14, 1926
2) April 10, 1887
April 10, 1888
   April 10, 2015
4) April 9, 1923
5) April 8, 1993
6) April 7, 1899
April 7, 1956
8) April 6, 1916
April 6, 1917
April 6, 1924
April 6, 1940

Latest Ponkapoag Pond Thaw Date, (1886-2015)

1) April 11, 2015
2) April 10, 1926
3) April 9, 1923
4) April 6, 1940
5) April 5, 1916
April 5, 1924
7) April 4, 1967
April 4, 1994
9) April 3, 1904
April 3, 1920

 

 

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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
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