What are the sources for WeatherOnline forecasts?


The WeatherOnline forecasts are created by using a MOS system developed in-house with the most current US weather services model data (GFS). The statistical methods of the Model-Output-Statistic (MOS)-System were developed in cooperation with the Meteorological Department of the University of Bonn.

What is a MOS-System?


A Model-Output-Statistic (MOS)-System combines the data of the weather forecast model and the locally recorded data for any given point by transforming the model data from a coarse grid to detailed small scale areas.
In order to do so, one needs a large volume of past model forecast data as well as the corresponding recorded data for any given location. The MOS-System relates these two sets of data in an optimized fashion allowing development of the local weather forecast by using the most current model forecast.

What are the time intervals used in the temperature and icons of the local forecasts?


The forecasted maximum temperature always refers to a 12hour window from 6am to 6om local time.
The forecasted minimum temperature always refers to the 12hour window from 6pm of the day before the forecast day to 6 am of the forecast day.
The weather icon for the morning refers to the time between 6am and 12pm local time, the icon for the afternoon is valid from 12am to 6pm local time and the evening icon refers to the time from 6pm to 12am local time.

How often are the current weather conditions and forecasts updated?


The current weather information as well as the satellite images are updated every 30 minutes whereas the radar images are being updated every 15 minutes.
The local weather forecasts as well as the weather charts are updated 8 times a day. The updates start at 2 am CEST or 3 am CEST depending on daylight saving time and continue on a three hourly bases.


Nearby Weather Stations - Derry Distance
Hanscom Field 14.9 km
Manchester 16.8 km
Lawrence Airport 19.5 km
Nashua Airport 26.2 km
Concord Airport 26.6 km
Norwood Memorial Airport 27.4 km
Laconia Airport 28.5 km
Milton 31.9 km
Logan Intl. Airport 33.5 km
North Central State Airport 41.3 km
Beverly Regional Airport 42.2 km
Skyhaven Airport 43.1 km
Rhode 44.2 km
Taunton Airport 47.1 km
Quonset State Airport 48.0 km
Newport State Airport 48.2 km
Mount Washington Airport 49.4 km
Portsmouth International Airport at Pease 52.5 km
Fitchburg Airport 53.3 km
Eastern Slopes Regional Airport 56.1 km
New Bedford Regional Airport 57.0 km
Mount Washington Regional Airport 60.1 km
Plymouth Airport 61.4 km
Berlin Regional Airport 61.9 km
Sanford Seacoast Regional Airport 65.8 km
Block 69.4 km
Worcester Airport 70.2 km
Plymouth Airport 70.5 km
Westerly State Airport 79.3 km
Jaffrey Airport 79.8 km
Martha's Vineyard Airport 91.7 km
Montauk Airport 95.1 km
Otis Air National Guard Base 96.4 km
St. Johnsbury 97.7 km
Caledonia County Airport 100.9 km
Sherbrooke Airport 101.1 km
Groton 101.1 km
Lenoxville 105.7 km
Windham Airport 107.9 km
Dillant 109.5 km
Orange Airport 110.0 km
Portland 111.2 km
Thetford Mines Rcs 113.1 km
Lebanon Airport 116.1 km
Auburn/Lewiston Airport 119.2 km
Cape Cod Gateway Airport 119.9 km
Provincetown Airport 122.5 km
Northeast Kingdom Intl. Airport 126.4 km
East Hampton Airport 126.9 km
Magog 129.1 km
Beauceville 132.3 km
Hartness State Airport 138.2 km
Ste Foy (U. Laval) 139.2 km
Québec 140.0 km
Westover Metropolitan Airport 141.1 km
Beauport 141.9 km
CFB Valcartier Airport 144.7 km
Chester Airport 145.6 km
Lemieux 146.9 km
Nantucket Memorial Airport 148.2 km
Chatham Airport 149.6 km
Edward F. Knapp State Airport 149.9 km
Deschambault CS 153.5 km
Hartford Airport 157.1 km
Morrisville- Stowe State Airport 158.9 km
Bradley Intl. Airport 159.2 km
Westfield-Barnes Regional Airport 161.5 km
Francis S. Gabreski Airport 164.4 km
Augusta State Airport 173.5 km
Meriden Markham Airport 177.2 km
Wiscasset Airport 179.5 km
Trois-Rivières 180.9 km
Rutland- Southern Vermont Regional Airport 186.9 km
Tweed New Haven Airport 186.9 km
Waterville Robert LaFleur Airport 189.2 km
Frelighsburg 189.5 km
Brookhaven Airport 189.9 km
Nicolet 190.6 km
Shawinigan 204.7 km
Middlebury State AP 205.2 km
Harriman-and-West Airport 209.7 km
Waterbury 211.6 km
Greenville (Amos) 212.3 km
Lake Saint Pierre 214.0 km
Franklin County State Airport 214.0 km
Sikorsky Memorial Airport 214.0 km
Long 214.3 km
Burlington Intl. Airport 214.6 km
William H. Morse State Airport 217.1 km
Pittsfield Airport 223.2 km
L'Acadie 242.2 km
Knox County Regional Airport 247.1 km
Republic Airport 248.3 km
Danbury Airport 250.0 km
Plattsburgh Intl. Airport 250.4 km
Saint-Hubert Airport 253.5 km
L’Assomption 258.7 km
Floyd Bennett Memorial Airport 260.2 km
McTavish 270.3 km
Sainte-Clotilde 276.1 km