Average temperature line graphs and Departure from average precipitation bar graphs, by month, for Brownsville, Harlingen, and McAllen, calendar year 2012

Temperature and Precipitation Trends Brownsville, Harlingen, McAllen, in 2012 Heat and Drought continued to be a dominant weather story in 2012. The charts below show monthly Temperature averages (left, line charts) and Precipitation departures from average (right, bar charts) through the year. Averages and departures are based on the data sample of record, which dates back to 1878 for Brownsville, 1911 for Harlingen, and 1941 for McAllen. Every month was above the long term average for temperature; all but February were below the long term average for precipitation at each primary site. Notable are the departures from average precipitation in September; the March departure above average at McAllen/Miller was strictly due to more than 4 inches of rain associated with the massive hailstorm on the 29th. Yet another dry summer and autumn ensured that reservoirs and other water supplies will cause severe water restrictions for irrigation, and likely for residences, by spring and early summer of 2013. At this point, only rains from frequent tropical waves or one or two tropical cyclones can ease some of the worst drought conditions on record for the Rio Grande Valley.