Quick Start •
Overview •
Degree Day Products •
Printing Reports •
More Information
This web site provides access to thousands of daily maximum and minimum
temperatures for 14 cities in the state of Wisconsin, USA. Detailed reports are
available by month from September 1990 to the present. Reports are
available about one month after the last day of the report month. Use the
Data Status page to determine the most recent
month available. The following cities are represented:
This Web site uses Microsoft's Active Server Pages to render the reports and
an Active Data Object connector to access the Microsoft SQL Server 7.0 database where
the maximum and minimum teperatures are stored. Instead of storing thousands of
HTML pages for years of weather data, this Web site creates the Web pages on demand.
Heating & Cooling Degree Days •
Daily Average Temperatures •
Growing Degree Days
To create a Heating & Cooling Degree Days report, select
city (weather station), month and year. Then click the
Submit button at the bottom of the page.
Heading titles used in the Heating & Cooling Degree Days
report:
Summary titles used in the Heating & Cooling Degree Days
report:
Refer to both the heading and summary titles when reading the summary values
at the bottom of the report.
To create a Average Daily Temperatures report, select city
(weather station), month and year. Then click the Submit button at
the bottom of the page.
Heading titles used in the Average Daily Temperatures
report:
Summary titles used in the Heating & Cooling Degree Days
report:
To create a Growing Degree Days report, select city (weather
station), month and year. Then click the Submit button at the
bottom of the page.
Heading titles used in the Growing Degree Days report:
Summary titles used in the Growing Degree Days report:
Refer to both the heading and summary titles when reading the summary values
at the bottom of the report.
Heating and Cooling Degree Days Using Adjusted Balance Point
Some applications like home energy audit systems require using a base cut-off
temperature other than 65º. This feature allows you to adjust the "balance
point" to match these unique requirements. You can also use adjusted cooling
degree days as growing degree days for points other than the 40º and 50º that is
provided by the
Growing Degree Days product.
The slide at the lower-left corner of the input form allows adjustments from
55º - 80º. Be sure to select item #4 for adjustable heating degree days and #5
for adjustable cooling degree days. Adjustable heating and cooling degree days
are displayed on separate reports.
To create an Adjusted Heating & Cooling Degree Days report, select
HDD using Adjusted Balance Point or CDD using Adjusted Balance
Point. Then select city (weather station), month, year
and Balance Point. Click the Submit button at the bottom of the page to
display the report.
The report headings and interpretation are very similar to
Heating & Cooling Degree Days.
Quick Start
Overview
ARLINGTON
ASHLAND
BELOIT
EAU CLAIRE
GREEN BAY
HANCOCK
LA CROSSE
LANCASTER
MADISON
MARSHFIELD
MILWAUKEE
RHINELANDER
SPOONER
STURGEON BAY
Degree Day Products
HDD and CDD with Adjusted Balance Point •
Normal Temps & Degree Days •
Download Normal Temps in CSV Text Format •
Download Max & Min Temps in CSV Text Format •
Heating and Cooling Degree Days Zone Summaries
1-Heating & Cooling Degree Days
Day
Day of the month
Max
Maximum temperature for the day
Min
Minimum temperature for the day
Avg
Average temperature for the day
HDD
Heating degree days
CDD
Cooling degree days
Cum
Daily cumulative degree days for the month
Avg
Average temperature for selected month
Norm
Normal temperature and degree days for selected month
Dep
Positive or negative departure from monthly normal
Max
Maximum temperature or degree days for selected month
Min
Minimum temperature or degree days for selected
month
2-Daily Average Temperatures
Day
Day of the month
Average Temp
Average temperature for the day
Avg
Averages for selected month (refer to column headings)
Norm
Normal temperature for selected month
Dep
Positive or negative departure from normal monthly temperature
Max
Maximum temperature for selected month
Min
Minimum temperature for selected month
3-Growing Degree Days
Day
Day of the month
Max
Maximum temperature for the day
Min
Minimum temperature for the day
Avg
Average temperature for the day
Growing 40 Base
Growing degree days computed with a base of 40
Growing 50 Base
Growing degree days computed with a base of 50
Corn Grow 50/86
Corn growing degree days computed with a minimum base of 50 and a maximum base of 86
Cum
Daily cumulative growing degree days for the month
Avg
Averages for selected month (refer to column headings)
Norm
Normal temperature and degree days for selected month
Dep
Positive or negative departure from monthly normal
Max
Maximum temperature or degree days for selected month
Min
Minimum temperature or degree days for selected month
4-HDD using adjusted Balance Point
5-CDD using adjusted Balance Point
Normal temperatures and degree days represent the latest 30 year averages available from the National Oceanographic and Atmospheric Administration for the fourteen Wisconsin cities available at this site. These averages are used for determining the departure from norm in the other reports.
To create a Normal Temps and Degree Days report, select Item 6, the city and press the Select button.
To download Normal Temps and Degree Days in comma seperated values text format (a CSV text file), select Item 7, the city and press the Select button. Field names are contained in the first row of the data.
To download maximum and minimum temperatures select the city (weather station), month and year. Select Item 8 for 1 month of data or Item 9 to download 12 months of data, then click the Submit button at the bottom of the page. Field names are contained in the first row of the data. Less than 12 months of data may be returned of you select a date less than a year before the most recent month available for your selected station. Use the Data Status page to determine the most recent month available.
Heating and cooling degree days zone summaries are available for eleven geographic areas in Wisconsin that experience very similar temperatures throughout the year. A population weighted State average is also available when you select the Pop Weighted reports.
If you do not live close to one of the fourteen available weather stations provided here, you can use the zone summaries with some assurance that the heating and cooling degree days are representative of normal terrain areas in your area.
The following table depicts the weather stations used for zone reporting. Notice that Zone 3 is listed twice. That is because Zone 3 is an average of both Rhinelander which is inland, and Green Bay on the shores of Lake Michigan. (Zone 3 does not have good full time weather stations and is influenced by both cold inland temperatures and maritime weather from Lake Superior and Lake Michigan).
ZONE | Wx STATION |
1 | ASHLAND |
2 | RHINELANDER |
3 | RHINELANDER |
3 | GREEN BAY |
4 | SPOONER |
5 | MARSHFIELD |
6 | GREEN BAY |
7 | EAU CLAIRE |
8 | HANCOCK |
9 | LANCASTER |
10 | MADISON |
11 | MILWAUKEE |
To create a Heating or Cooling Degrees Zone Summary report, select month and year and click the Submit button at the bottom of the page.
Population Weighted (Pop Weighted) Zone Summaries use the a ratio of the latest available population counts in the zone to total State population to calculate the State Population Weighted Heating and Cooling Degree Days.
A map of Wisconsin degree day zones is available from the menu bar.
From your Web browser select File | Print to print a displayed page.
All report products can be printed on a single 8 1/2 x 11 inch portrait sheet if the top and bottom margins are not too big and the text size is set to medium. Select File | Page Setup and set all margins to .5 (1/2) inches. If the page is still printing on two pages instead of one, decrease top and bottom margins or the text size until the report fits onto one page.
What is a Degree Day?
Degree Day is simply a way of measuring how hot or cold it has been over a
24 hour period. Whenever the average, (or mean) temperature is below 65 degrees
Fahrenheit, you have a heating degree day.
Whenever the average is above 65 degree Fahrenheit, you have a
cooling degree day.
If in a 24 hour period the high outside temperature was 70 degrees and the low was 50 degrees, then the average temperature for that day was 60 degrees - halfway between 70 and 50 degrees. This is 5 degrees less than the base temperature of 65. Therefore we can say that there was 5 heating degree days for the period.
if in a 24 hour period the high outside temperature was 80 degrees and the low was 60 degrees, then the average temperature for that day was 70 degrees - halfway between 60 and 80 degrees. This is 5 degrees more than the base temperature of 65. Therefore we can say that there was 5 cooling degree days for the period.
There is a direct relationship between heating degree days and the amount of energy required to heat a residence. The higher the heating degree days, the higher the fuel bill to heat a typical home. The opposite is true for cooling degree days. Once the daily average temperature is above 65º, homes start using air conditioning. Higher cooling degree days means the air conditioner stays on longer to keep the residents comfortable resulting in higher cooling costs.
What is Average Temperature?
Average temperature is the maximum and minimum temperatures for the day
divided by two and rounded to the nearest degree. At .5 the value is rounded up.
What is Growing Degree Days?
Growing degree days use the same formula as Cooling Degree Days, but uses a
base cut-off temperatures lower than 65º. The base depends on the crops that are
grown in the area. Corn growing degree days is a bit more complicated in that
corn growth in Wisconsin stops if the temperature never reaches 50º or remains
above 86º, and has various values when the max and min are between 50º and 86º
Fahrenheit. This system presents a report for 40º, 50º, and corn growing using
50º and 86º. Other growing degree days can be calculated by selecting
CDD Using Adjusted Balance Point.
Growing Degree Days base 40 calculation
gdd = Growing Degree Days
average = maximum + minimum temperature / 2
gdd = Round( average - 40)
if gdd < 0 Then
gdd = 0
End If
Growing Degree Days base 50 calculation
Corn Growing Degree Days calculation
If Low <= 50 Then
gdd = Growing Degree Days
average = maximum + minimum temperature / 2
gdd = Round( average - 50)
if gdd < 0 Then
gdd = 0
End If
Low = Low temperature for the day
High = High temperature for the day
cgdd = Corn Growing Degree Days
If Low <= 50 AND High <=50 Then
cgdd = 0
End If
If Low > 50 AND High > 50 Then
If High > 86 Then
cgdd = Round((Low + 86)/2 - 50)
Else
cgdd = Round((High + Low)/2 - 50)
End If
End If
If High > 50 AND High <= 86 Then
cgdd = Round((50 + High)/2 - 50)
End If
If High > 86 Then
cgdd = Round((50 + 86)/2 - 50)
End If
End If
if cgdd < 0 Then
cgdd = 0
End If
Degree Day Database Tables
Each station record contains the maximum and minimum temperature in degrees
Fahrenheit (Fº) for each day. The database also contains the 30 year normal
maximum and minimum temperature for the same stations. This allows reporting of
the departure from normal for: