Temperature and rainfall observations have been taken near the current site of the official KHSV ASOS since 1894. However, the Huntsville Weather Bureau (NWS/WSO) office was only formally commissioned in 1958, and the present POR for reporting extremes and averages essentially begins at that time. In a joint investigation, WFO Huntsville and the Office of the State Climatologist have generated a temperature data history beginning in 1907 using daily observations taken in the area of SW Madison County. Precipitation data begins in 1894.
Is the older data viable?
A scientific paper, appearing in the Bulletin of the American Meteorological Society, addressed the compatibility of summer maximum temperatures for all stations within Madison and adjacent counties of north central Alabama (Christy 2002.) Any change in the observational setting (location, time of observation etc.) was documented and a bias was calculated relative to the KHSV ASOS based on overlapping observations with many stations through time. On average, the stations of 014976 and 014068 were -0.16 °F and +0.35 °F respectively different than the current KHSV ASOS. These values being less than 0.5 °F are not significantly different than the mean measurements currently being made by the ASOS, suggesting these two stations are useful in extending the POR back to 1907.
Temperature and rainfall observations have been taken in the Florence/Muscle Shoals metro area since 1893. Cooperative stations in Florence and Tuscumbia covered the area until 1940, when an official station was commissioned in Muscle Shoals. Again, the data was deemed to be useful and so earlier data from Florence was combined with the more recent data from Muscle Shoals to create the new record - a truly metropolitan area record of weather conditions.
Is all the data there?
No. In the course of our study, we eliminated any suspect data from either dataset. This does lead to small data gaps in both locations, especially in the early 1900's. However, we feel we have the best possible representation of weather conditions, and that the new dataset is a significant improvement over the previous dataset due to the expanded period of record.
Daily climate reports (CLI) for Huntsville and Muscle Shoals are issued twice daily, around 2:00am and 4:30pm. These reports are available from the climate home page. Preliminary monthly climate data (CF6) for Huntsville, Muscle Shoals, and Decatur are updated daily around 5:00am, and are also available from the climate home page. Climate may be heard on the Huntsville and Florence NWR transmitters between 5:30am-8:00am and 4:45pm-7:15pm (CST) daily. The monthly climate report will be issued as soon as possible after the first of the month, and generally before the 5th day of the month.
We also issue a Regional Temperature & Precipitation Table (RTP) at 6:30am and 6:30pm (CST). This will be the running source of the morning low and daytime high, with the final numbers appearing on the 2:00am daily climate summary.
Questions about the new climate records?
We're glad to answer them! Email us at firstname.lastname@example.org.