Getting Started

This website was produced as a way to view long-term trends in data measured by the NYS Mesonet. Averages used in these products are based on 10-year averages of Mesonet data. To get started viewing data, choose an option from the menu or below.

Calendar

The calendar allows you to view long-term average data or daily observed data in a calendar format. When viewing temperature data for a specific year, the calendar can be changed to display the anomaly from the 10-year average. Anomalies allow you to see which time periods were above or below the 10-year average.

Graphs

Graphs are best for visualizing data at a specific Mesonet station. Graphs can be viewed for a single year in comparison with the station's 10-year climatology, or across multiple years to examine long-term patterns and variability.

Maps

Maps are best for visualizing data over the entire state over a variety of time periods. All Mesonet stations, provided that they have a sufficient data record, are included on the maps. Maps have two display modes: Across Periods and Across Years.

Across Periods

You choose a year (or the default 10-year average), and maps for every month, season, and full year are displayed.

Across Years

You choose a time period (months, seasons, full year), and maps for each year over that time period are displayed.

You can also choose the product category (temperature, precipitation, etc) and the product (average high, average low, etc). When your choices warrant, you also have the option to toggle between actual values (the default) or the anomaly from the 10-year average. Anomalies allow you to quickly see which time periods were above or below the 10-year average.

Methodology

These products are based on 10-year averages of Mesonet data. The method we have used in the calculation of these data closely follows the WMO Guidelines on the Calculation of Climate Normals. Statistics are recalculated each day, and values are subject to change. This website was produced as a way to view long-term trends in data measured by the NYS Mesonet.

Period Averages

Monthly, seasonal, and yearly averages are shown only when at least 70% of the days in that period have valid data. If 30% or more of the days are missing, or if 15% or more consecutive days are missing, the average is not calculated. This requirement applies only to average values and does not apply to totals (such as precipitation) or extreme values (such as the highest or lowest temperature).

Long-term Averages

Historical averages for each period are calculated only when enough data is available. At least 80% of the years in the averaging period must have valid data, with a minimum of 8 valid years required to calculate the long-term averages. This applies to all parameters.

Disclaimer

Users are cautioned against using these values for climate planning purposes. NOAA's National Centers for Environmental Information (NCEI) produce the U.S. Climate Normals dataset, based on the last 30 years of data, updated every 10 years. The Climate Normals dataset is the appropriate dataset to use for long-term, climate-based planning purposes.