Minneapolis and St. Paul (1871-1938)
On Feburary 9, 1870, President Ulysses S. Grant signed a law that required the U.S. War Department Signal Service to record weather observations "at the military stations in the interior of the continent and at other points in the States and Territories...for giving notice on the northern (Great) Lakes and on the seacoast by magnetic telegraph and marine signals, of the approach and force of storms".
In January of 1871, the St. Paul branch of the Signal Service began recording weather observations for the Twin Cities area. These official observations were relayed daily via telgraph to Washington, D.C. where maps were made of nationwide conditions. This network of reporting stations "signaled" the start of the U.S. Weather Bureau, which later became known as the present day National Weather Service.
U.S. War Department, U.S. Army Signal Service Weather Map, September 1, 1872 (Courtesy of NOAA Photo Library)
Between Jaunary 1, 1871 and November 6, 1890 the U.S. Army Signal Service office in downtown St. Paul served as the official weather station and observing site for the Twin Cities. Weather instruments were located in a white shelter on the roof of the 3-story Chamber of Commerce building and readings were taken three times a day. By 1888 the following weather elements were recorded at the site: barometric pressure, temperature, humidity, wind, and state of the sky. Instruments were also located on site that could record the highest and lowest temperature of the day in addition to the "rate of wind at all times". During the navigation season, the river level was also recorded.
The St. Paul weather office maintained a flag pole where "weather signal flags" were displayed each day. The color and shape of the flag represented the weather conditions expected over the next day or two. The four flags (which could be displayed singly or in combination) included a white square flag which represented clear or fair weather, a blue square flag which forecasted rain or snow, a white square flag with a black square center which represented a cold wave, and a black triangular flag which was hung above the other flags to signify warm weather and below the other flags to signify cold weather. The order of the forecasted weather event was read from top down. As an example, if the pole had a black triangular flag on top, a blue square flag in the middle, and a white square flag with a black square center on the bottom, the forecast was for a warm period with rain or snow followed by a cold wave.
In 1890, weather functions of the U.S. Army Signal Service Corps were transferred to the Department of Agriculture and assigned to the newly created U.S. Weather Bureau. On September 23, 1890 a branch of the Weather Bureau opened in Minneapolis at the new U.S. Court House and Federal Building at the corner of 3rd Street and 1st Avenue (now Marquette Avenue). On November 6th, the official weather observation site was transferred to the Minneapolis office. Shortly after the Minneapolis office opened, officials considered closing the St. Paul office. However, after local citizens and businesses protested the closure, both offices remained opened.
The U.S. Courthouse in downtown Minneapolis, home of the Weather Bureau from 1890 to 1965 (Courtesy of the Minneapolis Public Library, Minneapolis Collection).
Therefore, between 1890 and 1938, there were two Weather Bureau offices operating in the Twin Cities. Each office had a distinct role in weather observation and forecast operations during this time. The St. Paul office was responsible for creating local weather forecasts and for relaying and receiving weather data from Weather Bureau Headquarters in Washington D.C. The Minneapolis office was responsible for recording and archiving local climate data and distributing weather forecasts created by the St. Paul office.
During the late 1800s and early 1900s the primary way to distribute weather forecasts to local citizens was by mail. Each morning around 10:30 AM the St. Paul Weather Bureau would call its Minneapolis counterpart with the latest forecast derived from large scale weather maps created by Weather Bureau headquarters in Washington D.C. The Minneapolis staff would print the local forecast on postcards which were given to the co-located Minneapolis Post Office for distribution to nearby communities. In addition, both Weather Bureau offices maintained an extremely popular "large blackboard weather map" at their city's respective chamber of commerce buildings for local merchants to view on a daily basis. When radio stations took to the airwaves in the 1920s and 1930s, many people began to receive Weather Bureau forecasts in this manner.
A Weather Forecast Postcard printed by the Minneapolis Weather Bureau office on October 18, 1928 (Courtesy of the State Climatology Office, Minnesota Department of Natural Resources - Division of Waters)
In 1934, the Weather Bureau opened a new branch office at Wold-Chamberlain Field on the grounds of the present day Minneapolis-St. Paul International Airport. This new office was responsible for supporting the rapidly growing aviation community by taking weather observations and relaying weather forecast information. In fact the site of official weather observations was transferred from the downtown Minneapolis office to the Wold-Chamberlin Field Weather Bureau office on April 9, 1938..
In addition, the downtown St. Paul Weather Bureau office was moved to nearby Holman Field Airport around 1930 to help aviators. As a result of this shift in focus, the responsibility for creating local weather and river forecasts was transferred from the St. Paul office to the downtown Minneapolis office during the 1940s. The St. Paul office closed its doors in 1953 when advances in communication allowed local airport staff to receive weather information from the Wold-Chamberlain Field office.
In a 1947 report, the downtown Minneapolis office noted that it was the "depository station for all Minnesota climatological records, a corn and wheat region center for crop reports and the issuing of crop weather bulletins, and the river center for the Mississippi River and tributaries above Dam No. 2 at Hastings, Minn." During the late 1940s, local weather and river forecasts responsibility was shifted to the airport Weather Bureau office.
In March of 1965 the downtown Minneapolis Weather Bureau office was closed. The remaining staff at the downtown office who were responsible for climate services transferred to an office on the campus of the University of Minnesota. These staff members remained federal employees until the climatology program was turned over to the State of Minnesota in May of 1973. Today this agency is called the State Climatology Office and is funded by the Minnesota Department of Natural Resources - Division of Waters. Click here to visit their website.