After a dry April, May 2005 brought more Spring showers and thunderstorms with an unsteady, yet improving trend in rainfall. The most rain in the month came in early May; for 2 days in the middle of May; and late in the month from May 26 to the predawn hours of May 30.  Similar to April, May 2005 showed some variability in week to week weather changes. May 1st to 8th was much cooler than normal.  This was a result of the following weather patterns:  May 1st to 3rd was cooler than usual after the strong April 30th cold front; very cloudy days occurred from the 4th to the 8th; and a cool front with rain came through the area on May 8th.  Early morning lows on May 1st fell to mainly the 40s, with near 40 over the hill country to parts of Central Texas to some lows around 50 to low 50s near the Rio Grande around Del Rio. 

By May 9th and 10th, the tide slowly changed to more sunny days and less rain, except for a brief spell of thunderstorms the evening of the 9th over Llano and Gillespie Counties and from showers and thunderstorms on the 14th to the 15th and part of the 16th. From May 17th to 25th, very dry conditions like April returned, along with steadily warmer days. Some of the warmest days of the month and so far for the year showed up the 21st to the 25th, as a mid to late May ridge aloft built over the area from the west, also seen in May of 2003 and May of 2004. The dryness ended in late May, from the 25th to the predawn hours of May 30th, bringing another period of scattered showers and thunderstorms, with periods of heavy rain and severe weather. The rains that came in late May, helped to keep May 2005 out of one of the drier Mays of record. As helpful as these rains were, if the rain had been distributed more evenly in the month, then May 2005 rainfall would have been more beneficial. 

To no surprise though the late month rainfall catch up is typical of what Mays can bring. May is the wettest of all 12 months using average rainfall statistics for Austin and San Antonio, not only from the latest 30 Year Normal, also for the long term average of all Mays since the beginning of rainfall record, that dates back to 1856 for the Austin City Climate location, Austin Mabry; to 1943 for May at Austin Bergstrom;, and since 1871 for San Antonio.  It is not just the average that makes May the wettest of all months, also the Median Rainfall for May is the highest for all 12 months for Austin and San Antonio. For Del Rio a slightly different yet similar pattern emerges. The average May rainfall is the 2nd wettest of all 12 for Del Rio, using the 1971 to 2000 30 year normal and long term rainfall record, that begins in 1906 at Del Rio for May. The Median Rainfall at Del Rio tells a slightly different point of view in that May Median Rainfall at Del Rio is the highest of all 12 months. 

Despite all these climate statistics, after the end of the 31 day month, May 2005 ended up at San Antonio, with 2.97 inches, 1.75 inches below normal, and at Del Rio with 2.49 inches of rain, 0.18 inches above normal.  For Austin, May 2005 ended up at Austin Bergstrom with 3.10 inches, 2.02 inches below normal and at Austin Mabry, with 3.13 inches, 1.90 inches below normal. Monthly rainfall at other locations scattered across Central and South Central Texas for May 2005 was as follows: Burnet Airport 3.60 inches; New Braunfels Municipal Airport 2.51 inches; San Antonio Stinson Field 4.60 inches; and Hondo Municipal Airport 3.48 inches. Rainfall for Year 2005 from January 1st to May 31st was below normal at Austin, and San Antonio, and slightly above normal at Del Rio.  From January 1st to May 31st, Austin Bergstrom has had 13.13 inches of rain, 1.21 inches below normal; Austin Mabry 12.61 inches or 0.95 inches below normal; Del Rio 6.61 inches, 0.10 inches above normal; and San Antonio 9.59 inches, 3.03 inches below normal.

May 2005 had severe weather events on the 8th, 9th, 14th, 15th, 28th, 29th, and in the predawn hours of the 30th. Another severe weather event came after Midnight on the 31st, bringing a stormy and wet start to June 2005, during the early morning hours of June 1st.

After the strong cold front of April 30th, cool overnight lows came May 1st, where the low at Austin Bergstrom was 42, a Record Low for the Month of May and for May 1st.   Lows on May 1st were in the 40s at other locations also, with low 50s near the Rio Grande.  May 1st to 8th was a cloudy period in the month, as southwest winds aloft carried multiple layers of high clouds over the area, while storm tracks to the north enhanced the usual low clouds over the area. A cool front moved close to the area May 3rd and 4th, stalling over the northern hill country the 4th, and then was pushed north May 5th. On the weekend of the 7th and 8th one of the first  significant rain events for the month came to the eastern half of the area. By May 9th, a pattern of sunnier and warmer days tried to show up;  however, this was temporarily delayed.  During the late afternoon and early evening of May 9th a severe weather event developed over Llano and Gillespie Counties, as a strong thunderstorm developed into a cluster of super cell thunderstorms, and left large hail over parts of Llano and Gillespie Counties. The storms diminished after sunset. The drier trend increased the 10th to the 13th, and then slowed down May 14th and 15th. On May 14th and 15th the west half of the area picked up significant rains.  A rain event came the weekend of May 14th and 15th; however, most of the rain fell over the western half of South Central Texas. Locally heavy rains affected parts of Edwards and Val Verde Counties, while large hail was observed in Real County on the 15th. A line of storms formed south of Midland and moved south and southeast in the afternoon, bringing the rains and active weather.  On May 16th, rains tried to increase over the east part of the area; however, this broke down, and the dryness increased on the 17th to the 25th.

In the week of May 16 to 21, and continuing from the 22nd to the 25th, the days got steadily warmer, with a record daily high of 97 May 21st and 22nd at Austin Bergstrom. On May 24th and 25th, high clouds worked their way further east from West Texas, as the ridge aloft broke down and moved west and south. Early to Mid Morning showers on May 25th in Del Rio moved east and broke up by late morning. An area of showers and thunderstorms moved across the area on Thursday the 26th, from an upper level disturbance coming out of the west and northwest. This left scattered rains over the area, with one locally heavy rain event over the south part of San Antonio, where San Antonio Stinson Field picked up 2.81 inches of rain. More showers and thunderstorms came on the weekend of the 28th and 29th, with locally heavy rain and reports of severe weather.  One final wave of showers and thunderstorms continued into the predawn hours of the 30th. May 31st began as a calm and warm day, followed by increasing clouds in the evening, ahead of an area of thunderstorms that moved over the area after Midnight. This  made the beginning of June 2005, in the early morning hours of June 1st, wet and stormy.