Archived Weather Data

This site is no longer collecting historical data as of 10/1/24

Marquette, MI Normals

Station Records

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.

Official Weather Data

Marquette COOP Station (NWS site)

Forecast Accuracy

Check the accuracy of forecasted temperatures

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Notes:

General

• The above data, with the exception of normals, were produced by a private weather station located 1/4 mile south of downtown Marquette. The station went online July 10, 2015 and recorded data through September 30, 2024 after which point it went offline. As of late 2024, efforts are being made to locate a suitable replacement weather station to resume uploading historical data.
• If you're seeking official weather data for the Marquette COOP station (1857 - present), please visit NOAA NOWData.

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).

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.
• 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.

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 were updated monthly based on data beginning August 2015 (first full month of data collection).

Air Quality

• Air quality data collection began June 21, 2023. Each history table contains the Air Quality Index (AQI) and the adjusted AQI which appears on the City/home page. AQI is based on a PM_2.5 particle count. The scale is 0-500. The higher the AQI, the worse the air quality. We use a Purple Air PA-II with dual laser particle counters which are polled every minute. For an explanation of AQI please tap on the linked headline "Air Quality" on the City page (in the Weather Conditions section at the top/left).
• The values found in the history tables under the column header "ADJ AQI" represent adjusted AQIs. On July 31, 2024 we switched from an EPA correction factor to the "ALT-CF3" algorithm. The ALT cf=3 correction factor is said to better estimate the particle count for our sensor as compared to federal air quality monitors. It does not leverage any problematic proprietary formulas such as CF_ATM or CF1.
• As of 8/1/24 we have added adjusted PM_2.5 concentrations (µg/m³) to the Air Quality tab for each history table (daily/monthly/yearly). These are corrected data using the ALT-CF3 algorithm mentioned earlier. They correspond to the adjusted (ADJ) AQI figures. Calculations are performed on 1 minute instantaneous samples (not 10-minute averages).