Monthly Summaries

Monthly summaries are available as an HTML formatted page or as a downloadable PDF.  Station location information is provided on the top of the report while monthly averages and extremes are included at the bottom.  An asterisk (*) marks observations in which at least one observation is missing.  If too many observations are not available, NA is listed in place of the value.

Monthly summaries are available for each Mesonet station.  Data reflect measurements taken from midnight to midnight Central Standard Time (CST).

Most measurements require a minimum percentage of observations for the day to be included in the daily and monthly calculations.  Total daily solar radiation is calucated if 99% of the observations for the site and day are available.  Maximum wind gust, maximum heat index, and minimum wind chill are calculated if at least 1 observation is available for the day.  All other variables require at least 90% of the observations to be computed.


Site Information:

Site Name- The site name is usually the nearest incorporated city. Each site also
is designated by a unique 4-letter ID. The distance to the nearest town is listed
in miles.

Latitude and Longitude- The latitude and longitude of each station were
determined to the nearest second from Global Positioning System (GPS) units.
The numbers listed are degrees, minutes, and seconds, separated by dashes.
For example, 36-41-25 is 36 degrees, 41 minutes, and 25 seconds.

Daily Data (from left to right):

Temperatures (° Fahrenheit)- Maximum and minimum temperatures show the
highest and lowest 5-minute temperature observations reported during each
calendar day (CST). True maximum and minimum temperature may differ
slightly, but the 5-minute resolution will be very close. Average daily temperature
is determined using all available 5-minute observations during the day. It is
calculated by adding all of the temperature observations and dividing by the
number of observations for the day.

Dew Point (° Fahrenheit)- The dew point is the temperature to which the air
would have to be cooled to form dew. It is derived from measurements of
temperature and relative humidity and provides an estimate of the amount of
moisture in the air. Dew point is calculated for each 5-minute observation and
then averaged over the day.

Degree Days- Heating degree days (HDD) and cooling degree days (CDD) are
measures of the amount of heat which has to be added to (heating) or removed
from (cooling) the air to provide a "comfortable" temperature. Degree days
measure the departure of a day's average temperature from a base of 65
degrees. If the average temperature is below 65 degrees Fahrenheit, heating
degree days are added; if it is above 65 degrees, cooling degree days are added
as follows:

HDD = 65 - mean temperature
CDD = mean temperature – 65

Relative Humidity (Percent)- Maximum and minimum relative humidity are the
highest and lowest values, respectively, from any of the 5-minute observations
during the day (CST). Average relative humidity is the average of all 5-minute
values from the entire 24-hour period.

Rain (Inches)- The rain values are the 24-hour (CST) rainfall totals. Totals may
include any frozen precipitation (snow, ice, hail) which may accumulate in the
gauge and then melt during the current day. (There is no reliable and affordable
means of automating snow measurements.) Frozen precipitation cannot be
recorded until it melts; therefore, precipitation from snow may not be recorded
until several days after the snow event.

Pressure (Inches of Mercury)- The pressure values are the average daily value
(CST) of air pressure measured at the station (STN) and an estimated value
corrected to Mean Sea Level (MSL). The reason for the latter category is that
pressure is very sensitive to even small changes in elevation. To compare
pressure between sites, the observations have to be made (or estimated) at
a common level, in this case sea level.

Wind (Miles per Hour)- The direction listed is the most common wind direction
for the day. Each 5-minute observation of wind direction is recorded as from one
of the 16-point compass headings, and the heading with the highest number of
observations at the end of the day is listed on the form. Wind speed is an
average of all 5-minute observations during the day and is not dependent on the
direction. The maximum wind speed is the highest recorded observation from
any 3-second measurement.

Solar Radiation (Megajoules per Square Meter)- The solar radiation readings
reported by the Mesonet are the rate of solar energy hitting a square meter of the
earth's surface. Because the values are zero during nighttime, an average of the
5-minute reports would not provide much information. Therefore, the 5-minute
rates are converted to a 5-minute accumulation of energy. [Multiplying by 300
seconds for the 5-minute observation period converts Watts (Joules per second)
to Joules.] These 5-minute accumulations then are summed for the entire day,
yielding the total energy received over a square meter from the sun during the
day (expressed in Megajoules per square meter). An analogy is a car's
speedometer and odometer. The speedometer measures a rate of travel while
the odometer measures the total distance traveled. The rates reported by the
Mesonet stations are like the speedometer while the accumulations presented in
the summary are like the odometer. Factors which may affect the solar energy
accumulation include clouds, dust, smoke, fog, or other particles in the air.

Soil Temperatures (° Fahrenheit)- Observations are recorded at a depth of 10
centimeters (4 inches) under both bare soil and native vegetation (sod). The sod
and bare soil temperatures are daily averages from all observations for the day,
taken at 15-minute intervals. The maximum and minimum values are from the
bare soil temperature readings, which typically show more variability than the sod temperatures because the sod acts as insulation.

Monthly Data:

Monthly Averages- Numbers along the bottom of the daily columns show an
average of all the values in the column above it (with the exception of maximum
wind speed, which is the extreme for the month). For example, the maximum
temperature is an average of the daily maximum temperatures. The prevailing
wind is determined, as in the daily observations, by counting the number of
observations for each compass heading during the entire month and then listing
the most frequently observed wind direction.

Temperature- This value shows the highest and lowest of the daily maximum
and minimum temperatures for the specific Mesonet site during the month.
Degree Days- This value is a monthly accumulation of all of the daily degree day

Rainfall- Total rainfall is a sum of the daily rainfall totals. The greatest 24-hour
rainfall is the highest single-day total during the month.

Humidity- This value shows the highest and lowest of the daily maximum and
minimum relative humidity values.

Number of Days With- This table provides a quick-glance count of the number
of days on which certain weather conditions were recorded. Included are a count
of the number of days on which the maximum temperature equaled or exceeded
90 degrees (Tmax ≥ 90), the maximum temperature was at or below freezing
(Tmax ≤ 32), the minimum temperature was at or below 32 degrees (Tmin < 32),
and the minimum temperature was at or below zero (Tmin < 0). It also shows the
number of days on which precipitation was recorded (Rainfall ≥ 0.01 inch) or was
over one tenth of an inch (Rainfall > 0.10 inch).

Lastly, it provides a count of the number of days on which the average wind
speed was over 10 mph or the maximum wind speed exceeded 30 miles per

Missing Data:

Asterisk(*)- An asterisk in a data cell indicates that at least one observation is
missing for that day but less than 10% of the observations are missing.

Not Available (NA)- An "NA" in a data cell indicates that 10% or more of the
observations are missing for that day. These rare data outages can occur if
lightning strikes the site, a sensor malfunctions, or vandalism occurs.