LAST KILLING FROST PAST 37 SPRINGS (1980-2017)

This is information so buried that I spend hours digging it up. I'd rather dig in my garden!
To a tropical gardener a killing frost really kills a lot of your plants. Cover tender plants or bring them in if the forecast is for mid-30s or low 30s F.
The AVERAGE date for the LAST killing frost at Houston Hobby airport is February 14th each year.

YEARS WITH NO FREEZE in urban Houston or Hobby airport:
None/1999-2000
None/2011-2012 (in urban Houston)
None/2012-2013 (in urban Houston
None/2014-2015
None/2015-2016 (light frost on January 7th)
YEARS when a DECEMBER FREEZE is the last freeze of the winter:
12/13/1983
12/14/1997
12/25/1989
12/26/1985
12/26/2005
12/31/1990
YEARS  when a  JANUARY FREEZE is the last freeze of the winter:
1/8/2017
1/3/2008
1/5/1969
1/5/1999
1/13/2012 (Intercontinental Airport, but not inner city)
1/16/1992
1/17/2013 at Hobby but inner city Houston has had no freezes in 2013 
1/17/1997
1/19/2018 severe freeze of 19F
1/21/2001
1/24/2003
1/28/2004
1/29/2009
YEARS when a FEBRUARY FREEZE is the last freeze of the winter:
2/1/1949
2/3/1985
2/7/1984
2/9/1972 (Ellington Field)
2/10/1994
2/12/2011
2/12/1981
2/12/1988
2/12/2006
2/16/2007
2/25/2010
YEARS when a MARCH FREEZE is the last freeze of the winter:
3/4/2014 (0 years ago)
3/3/1980 (33 years ago)
3/5/2002 (11 years ago)
3/7/1989 (23 years ago)
3/7/1982 (31 years ago)
3/8/1995 (18 years ago)
3/10/1996 (17 years ago)
3/14/1993 (20 years ago)
3/17/1900 (113 years ago)
3/19/1923 (over 81 years ago)
3/31/1987 (26 years ago) latest freeze ever recorded in urban Houston/Hobby
YEARS WITH AN APRIL FREEZE:
NO APRIL FROSTS RECORDED AT HOBBY AIRPORT/ HOUSTON, TEXAS

Comparing the average last killing frost date of Feb.14, here are the numbers that are averaged together:
2017-2018~January 19th (early Spring)  NOTE: lowest 19F with multiple freezes on 11 other days (Rare snow on December 8th, 2017)
2016-2017~January 6,7,8th  23 degrees (early Spring) E (Lowest 23F severe/hard freeze)
2015-2016~No Freeze  (light frost on January 7th (Lowest 32F for one hour)
2014-2015~No Freeze
2013-2014~March 4th         (late Spring) L
2012-2013~January 17th      (early Spring) EE (Lowest 31F)
2011-2012 ~ January 13th    (early Spring) EE (Lowest 32F)
2010-2011~February 12th    (near normal) N  (Lowest: 23F)
2009-2010~February 25th   (late Spring) L     (Lowest 21F)
2008-2009~January 29th      (early Spring) E   (Lowest 32F)
2007-2008~January 3rd       (early Spring) EE  (Lowest 32F)
2006-2007~February 16th    (near normal) N   (Lowest 29F)
2005-2006~February 12th    (near normal)N
2004-2005~December 26th  (early Spring) E
2003-2004~January 28th      (early Spring) E
2002-2003~January 24th     (early Spring) E
2001-2002~March 5th        (late Spring) L
2000-2001~January 21st      (early Spring) E
1999-2000~No Freeze              (no frost)   EEE lowest: 33degrees
1998-1999~January 5th       (early Spring) EE
1997-1998~December 14th    (1 frost) EEE lowest: 32 degrees
1996-1997~January 17th      (early Spring) E
1995-1996~March 10th       (late Spring) L
1994-1995~March 8th         (late Spring) L
1993-1994~February 10th   (near normal)N
1992-1993~March 14th       (late Spring)L
1991-1992~January 16th      (early Spring)E
1990-1991~December 31st  (very early Spring) EE
1989-1990~December 25th  (very early Spring) EE
{Special NOTE: December 1989 remains one of the harshest winters in recent history with temperatures of 23F, 14F, and 9F recorded in the same month.
It also snowed that Christmas. Our son was a one year old and he had a White Christmas in Houston!}
1988-1989~March 7th     (late Spring) L
1987-1988~February 12th  (near normal) N
1986-1987~March 31st   (very late Spring) LL
1985-1986~December 26th (very early Spring) EE
1984-1985~February 3rd (early Spring) E
{Special NOTE: The winter of '85 was severe with lows of 20F, 21F, and 22F. Ice storm that year.}
1983-1984~February 7th  (early Spring) E
{Special NOTE: The winter of '83-'84 was especially harsh with a December sequence of 23F, 25F, 17F, 13F, 21F, 24F, 22F, 22F, and 20F. It was our first Christmas as a married couple and we were iced in. No one could visit or travel that year for the holidays.}
1982-1983~December 13th (very early Spring) EE one frost of 32F
1981-1982~March 7th (late Spring) L
{Special NOTE: January of '82 was especially harsh with a lows of 27F, 21F, 32F, 30F, 24F, 26F, and 15F. My car battery died out on the 15F day along the side of the highway.}
1980-1981~February 12th (near normal) N NOTE: low of 15F in February
1979-1980~March 3rd (late frost) L
1978-1979
1977-1978
1976-1977
1975-1976
1974-1975
1973-1974
1972-1973
1971-1972~February 9th (early Spring) E
1970-1971 no records available
1969-1970 no records available
1968-1969~January 5th    (very early Spring) EE
Older dates I've collected:
1948-1949~February 1st      (early Spring) E  Earliest Weather Record from Houston Hobby Airport
GALVESTON ISLAND LAST KILLING FREEZE
1947-1948
1946-1947
1945-1946
1944-1945
1943-1944
1942-1943
1941-1942
1942-1943
1943-1944
09
1922-1923~March 19th   (very late Spring) LL lastest freeze date for Galveston Island
1899-1900~March 17th  30degrees (very late Spring) LL
1891-1892~March 18th  27degrees (very late Spring) LL

So far, from the hundreds of dates I've looked at, the only patterns I've found are these:
1) once you have a day in Spring with a high of 78 to 80 degrees, you will have no frosts after that date.
2) We haven't landed on the average killing frost date in the past 22 years.
3) So far, there have not been three late Springs in a row, but there have been 3 early Springs in a row.
4) No two years share the same last date for a frost for the past 22 years! No wonder farmers have such a tough time figuring out when to plant their crops.
5) Last killing frost dates give NO CLUE to the severity of freezes for that winter. An early Spring could be in the same year with a low winter temperature of 14F for Houston! Imagine!

I have records dating back to 1948, but  I have to search each date individually on a weather website (ugh). I'll work on this each week until there is a complete record. Galveston, Texas goes back to the 1880s, but it is not online and I can only put the month, not the exact date.
David/:0)