Mina April Minimum Temperatures

I wanted to update a graph I made last year regarding April minimum temperatures in Mina, NV.

The April minimum temperatures are shown (using adjusted data), plus a three-year running average, to guide the eye.

Why Mina? Because it is in central Nevada, with a very low population, and unaffected by urbanization and the urban heat island effect.

Why April? Because April is a rather dry month in Nevada. The greenhouse effect is dominated by water vapor. The effects of the other greenhouse gases will be more evident if water vapor levels are at a minimum.

Why Minimum Temperature? Because the effects of greenhouse gases (other than water vapor) on raising temperature will be more pronounced when turbulence is at a minimum (mostly at night).

Last time, I noticed that temperatures increased sharply starting in the mid-70's, but the HCN Version 2 record ended in 1994, so I couldn't anything more than that. The updated HCN Version 3 record ends in 2011.

Some warming at this location appears evident, but the record looks more-complicated than I thought at first.

Citation:

3.1 GHCNM (version 2):

Peterson, T.C., and R.S. Vose, 1997: An overview of the Global
Historical Climatology Network temperature database. Bulletin of
the American Meteorological Society, 78 (12), 2837-2849

3.2 GHCNM (version 3):

J. H. Lawrimore, M. J. Menne, B. E. Gleason, C. N. Williams,
D. B. Wuertz, R. S. Vose, and J. Rennie (2011), An overview of the
Global Historical Climatology Network monthly mean temperature data
set, version 3, J. Geophys. Res., 116, D19121,
doi:10.1029/2011JD016187.