The first half of 2012 was the warmest January-June period for the Lower 48 States in records dating to 1895. That’s according to a report issued Monday by the National Oceanic and Atmospheric Administration (NOAA).

The national temperatures averaged 52.9 degrees – “4.5 degrees above the long-term average,” the NOAA report said. “Most of the contiguous U.S. was record and near-record warm for the six-month period, except the Pacific Northwest.”

Overall, a total of 28 states, all east of the Rocky Mountains, had record warm first six months of the year. Another 15 states had their top 10 warmest January-June periods. Washington was the only state that recorded a cooler than average first half of 2012.

Although a cool front has brought some relief this week, climate models suggest the warmer-than-normal temperatures are not expected to ease. “It looks like it’s going to stay above normal, for much of the remainder of the summer,” said Jon Gottschalck from NOAA’s climate Prediction Center.

In addition to a warm first half of the calendar year, the past 12-month period has been the hottest on record for the contiguous U.S., surpassing the mark set last month. In fact, the warmest 12-month period on record was set in March of this year and broken each successive month since then.

As hot as June was for many states, however, the month was only the 14th warmest on record for the Lower 48 States. The NOAA said that 170 American cities met or broke record-high temperatures during June. Temperatures of 113 in South Carolina and 112 in Georgia may become all-time state records after a review by NOAA.

The record heat has also been accompanied by a widespread drought. The NOAA report said the January-June period was among the 10 driest six month periods on record in 14 states, primarily the Great Plains states. June was also the 10th driest on record. The U.S. Drought Monitor indicates 56 percent of the contiguous U.S. is experiencing drought conditions.