marquetteweather.com
Highest recorded temperature: 95.7 °F on Sep 4, 2023
Lowest recorded temperature: -14.7 °F on Jan 31, 2019
Total recorded temperature range: 110.4 °F
Highest recorded pressure: 30.83 inHg on Jan 13, 2017
Lowest recorded pressure: 28.78 inHg on Dec 24, 2015
Total recorded pressure range: 2.05 inHg
Highest recorded wind speed: 51.0 MPH on Feb 24, 2019
Wettest day on record: Sep 5, 2018 with 3.11 in of rain.
Sunniest day on record: May 27, 2023 with 12.1 hours of sunshine.
The above data, with the exception of normals, are produced by a private weather station located 1/4 mile south of downtown Marquette. The station went online July 10, 2015.
If you're seeking official weather data for the Marquette COOP station (1857 - present), please visit NOAA NOWData.
24 hour graphs at the top of the page are updated every 5 minutes.
Daily and monthly history tables are updated along with the graphs every 5 minutes. Yearly histories are updated at the top of every hour.
Temperatures
"NWS" averages are the sum of the daily high temperature & daily low temperature in whole degrees divided by 2. This is the National Weather Service method used for climatological summaries. All other fields labelled "Avg" contain integrated averages using one minute samples. "Avg" labelled summary columns contain weighted means (i.e. a partial hour/day/month counts less than a full one).
CDD = Cooling Degree Days & HDD = Heating Degree Days. Degree days are calculated using daily NWS averages compared to a base value of 65°. For example, a day with an avg temperature of 67.7° will have 2.7 CDDs & 0 HDDs. A 33.2° avg temperature will produce 31.8 HDDs & 0 CDDs.
In the daily & monthly history tables, "Wind Chill" appears only October through April. It is calculated when the temperature is 50 or below and sustained wind speed is greater than 3 mph. Otherwise, it equals the temperature. Likewise, "Heat Index" appears only May through September. It is calculated only when the temperature is 80 or above. Otherwise, it equals the temperature.
Wind
"Sustained" wind is the rolling 10 minute average sustained wind speed.
"Wind Dir" is a scalar average of direction irrespective of speed. However, calm winds do not have a valid direction and are not included in the average.
"Wind Run" uses the 10 minute wind average.
"Low Sustained" & "Low Max" wind values are omitted from the yearly history table since every field equals 0.
Anemometer (wind gauge) was raised from 20 ft to 28 ft on June 18, 2017
Humidity / Dew Point
As of July 2018 daily, monthly, and yearly history tables contain corrected humidities and dew points. A custom correction curve addresses a dry bias above 95% and a wet bias below 92% inherent to the sensor. A third-party device accurate to within 2% humidity established the deltas used in the algorithm. The daily table contains up-to-date corrections for today. The monthly and yearly tables have corrections through yesterday (updated just after midnight each morning).
The 24 hour graphs contain corrected humidities & dew points.
Precipitation
"Liquid" precipitation in the winter is the amount of melted snow and/or ice.
Daily snowfall record keeping ran from October 2017 through December 2023. Snowfall is no longer measured.
The daily precipitation table doesn't contain hourly reports because often we correct the total with a measurement from our manual gauge. Unfortunately, when that happens, we have no way of reconstructing hourly amounts. For a raw, uncorrected breakdown of rain over the past 24 hours please see the precipitation graph at the top of the page.
Pressure
Since January 15, 2018, pressure is recorded in altimeter format. The home page, however, continues to display "Barometer" in MSLP format by default.
Solar
UV index measurement began June 6, 2020. Sensor detects ultraviolet radiation at wavelengths of 290 to 390 nm. Scale is 0-16 (but never gets above 11 in Marquette).
Solar radiation measurement began June 11, 2020. Scale for solar radiation is 0 - 1800 Watts per meter squared. This measurement of the sun's energy (detected between 300 and 1100 nanometers wavelength) can approximate daylight cloud cover relative to clear days for a given time of year. It's also useful for determining solar electricity generation and aerosol levels (pollution, smoke, dust, ash, etc).
The daily table summary footer for this tab omits "Min" since every value is always 0. Instead you'll see a "Daytime Avg" row displaying weighted averages of all hourly maximums, minimums, and averages between sunrise & sunset.
In monthly & yearly tables, you'll see a "Daytime Avg" column containing daylight averages. The "Min" column will be entirely missing since every value would be 0.
Total Radiation is measured in Megajoules (1,000,000 J) per meter squared.
Normals
"Depart" in the Normals table refers to the average departure (or difference) between our weather station and the official Marquette average temperature recorded at the Water Filtration Plant on Lakeshore Dr. These numbers are updated monthly based on data beginning August 2015 (first full month of data collection).
Air Quality
Air quality data collection began June 21, 2023. The table contains the Air Quality Index (AQI) and the EPA-adjusted AQI (which is the reading published on the City/home page). AQI is based on a 2.5 micron particle count. The scale is 0-500. The higher the AQI, the worse the air quality. We use a Purple Air dual-laser particle counter which records the 2-minute average AQI every minute. For an explanation of the ratings (not published here) that accompany AQI please tap on the linked headline "Air Quality" on the City page (in the Weather Conditions section at the top/left).
Sometimes my neighbor to the south burns trash (notable on days with a south wind). Also two doors down to the east is an Airbnb home with a fire pit. Burning events will be evidenced by a 1 hour spike in AQI. On such days, it is important to evaluate the daily average rather than maximum AQI.
