December was a very wet month and we are off to another active start to January.

In December, a trace or more of rain or snow fell on 27 out of 31 days. In total we measured just under 6 inches of precitipitation in the last month of the year.

So far this month, a trace or more of precipitation has been measured on 4 out of 7 days.

If you add up all those days, we have had a trace or more of precipitation in Indianapolis on 31 out of the last 38 days!

Each month, I receive an Astronomy newsletter from Indiana University. The newsletter is called Star Trak. Here is a link: http://newsinfo.iu.edu/cat/page/normal/216.html

When you get a chance, ask your kids tonight if Earth is closer to the sun in the winter or summer. I’m predicting they will say Earth is closest when we experience the warmest temperatures.

This month’s Star Trak answers that question:

On Jan. 4, Earth will reach its closest point to the sun in its orbit, the position called perihelion. A popular misconception is that our seasons are caused by Earth’s changing distance from the sun. The actual cause is the tilt of Earth’s axis. Winter in the Northern Hemisphere happens when the North Pole is tilted away from the sun, so that sunlight must pass through a greater amount of Earth’s atmosphere to reach the surface. We experience the coldest time of year when we are closest to the sun.

With temperatures and precipitation both forecast to be above average for the month, I thought it would be good to look at the extremes for the month. The measuring stick for snowfall is still 1978. Just over 30 inches of snow fell that month. I’m sure you have pictures of the Blizzard of ‘78!

The information below is from the National Weather Service office in Indianapolis. You can visit their site at http://www.crh.noaa.gov/ind/

Monthly Temperature and Precipitation Extremes for Indianapolis
(City Office from 1871 to January 1943…Airport from January 1943 to Current)

                             ..JANUARY..

             Coldest            Driest           Least Snow

           Year  Temp        Year   Precip      Year  Snowfall
           —-  —-        —-   ——      —-  ——–
           1977  10.3        1944     0.21      1937    0.0
           1918  14.6        1981     0.36      1960   Trace
           1940  16.7        1925     0.49      1944   Trace
           1912  17.2        1931     0.54      1942   Trace
           1970  17.9        1945     0.57      1989    0.1
           1893  17.9        1943     0.65      1933    0.1
           1979  18.0        1986     0.73      1919    0.1
           1978  18.2        2001     0.74      1932    0.2
           1963  19.5        1902     0.76      1973    0.4
           1875  19.8        1919     0.91      1923    0.6

             Warmest            Wettest          Most Snow

           Year  Temp        Year   Precip      Year  Snowfall
           —-  —-        —-   ——      —-  ——–
           1880  45.0        1950    12.69      1978   30.6
           2006  39.8        1890    10.20      1996   25.2
           1933  39.2        2005     9.39      1918   22.0
           1932  38.4        1937     8.05      1982   21.8
           1876  38.4        1907     7.68      1977   20.9
           1950  37.4        1913     7.63      1895   20.0
           1890  37.4        1949     7.41      1979   19.1
           1990  37.3        1930     7.34      1999   18.3
           1998  36.6        1916     6.55      1915   17.6
           1989  36.3        1999     6.35      1968   17.0

                   {Temperatures shown in Fahrenheit}
              {Precipitation and Snowfall shown in Inches}

I hope you all had a great holiday! The upcoming work week will bring a return to colder conditions to Central Indiana.

The most significant chance of precipitation will come on Tuesday when a storm system will impact the region. At this point there is considerable uncertainty regarding the track of the low pressure and the possible types of precipitation, but it seems a good bet that there will be at least a mixture of rain, freezing rain and snow across the area on Tuesday.

After the storm pulls east, much colder air will arrive from the northwest. This will send high temperatures plummeting, and they will only reach the 20s by Wednesday.

Both temperatures and precipitation are predicted to be above average this month. The maps above are from the Climate Prediction Center.

January is the coldest month of the year in Indiana. Our average low temperature drops to 18 degrees this month. The average high is around 34 degrees. This is also our snowiest month. Over 9 inches of snow usually falls in Indianapolis this month.