lake county climate
Introduction

Lake County lies in the southern part of Oregon along the California border. It is within both Climate Division 5 (High Plateau) and Climate Diviation 7 (South Central Oregon) established by the National Climatic Data Center. Below is a description of the climate of Division 5 and 7 followed by specific descriptions of Lake County. Climate tables for various parameters, as observed at long-term climate stations in Lake County, are included below.

Climate Division 5 — High Plateau

Oregon's High Plateau, a region bordered by the Cascades on the west and several minor mountain ranges on the south and east, comprises much of Klamath County and parts of Lake and Deschutes Counties. Due to generally high elevations, the Plateau has cool temperatures and receives a significant amount of snow. Its distance from the coast, coupled with its location downwind of the Cascades, causes its annual precipitation to be lower than in the mountainous areas surrounding it.

The Cascade crest, running north-south at a longitude of about 122deg W, is lower in elevation in the High Plateau than in most parts of Oregon. Only one peak, Mt. Thielsen, exceeds 9,000 feet. As a result, the 'rain shadow' effect produced by the mountains is less dramatic in this zone than in areas to the north. Another notable difference between the High Plateau and the surrounding zones is its average elevation east of the Cascades. Whereas the places east of the northern and central Oregon Cascade peaks are typically 2,000 - 4,000 feet above sea level, the lower elevations of the High Plateau average about 5,500 feet.

As air moves from west to east over the Cascades in Zone 5, it begins to descend; the greater the descent, the drier the air becomes. While air parcels reaching Bend to the north have descended about 4,000 feet from the crest and are usually quite dry, similar air parcels moving into the High Plateau drop only about 2,000 feet. This difference is reflected in the average annual precipitation total for these two areas. Bend receives only about 12 inches per year, while points in the High Plateau receive more than 20 inches.

The remoteness and ruggedness of the High Plateau has resulted in low area population. Only a few small towns, including Chemult, Silver Lake, and Odell Lake, serve as population centers; none exceeds 1,000 residents, however. Primary economic enterprises in the area include tourism (such as Oregon's only national park, Crater Lake), livestock raising (primarily beef cattle and sheep), and agriculture (includes alfalfa hay, grass and legume seed crop, and wheat).

Normal precipitation values in Zone 5 are dependent upon west-east orientation and elevation. Crater Lake, in the west, receives an average of more than 65 inches per year, while Fremont and Summer Lake to the east receive about 12 inches. Crater Lake's elevation is about 2,000 feet higher than the latter stations. Figure 1 shows NOAA climate stations in Zone 5, which were in operation during the 1961-1990 period. Figure 2 shows the Lake County region from the Oregon annual precipitation map. Table 1 lists normal monthly and annual precipitation totals at the Zone 5 climate stations. Table 2 list the average number of days with precipitation amounts exceeding certain thresholds.

Temperatures in Zone 5 vary considerably during each day and throughout the year. The Crater Lake weather station, highest in elevation, has the coolest temperatures. Average maximum temperatures at this point range from the high 60's in summer to the mid 30's in winter; lows are near 40 deg F in summer and high teens in winter (see Table 3). Summer Lake and Fremont are the warmest sites during the summer, and the latter has the coldest average low temperatures in winter.

The combination of high elevation and distance from the coast can produce cold temperatures in any month of the year for the High Plateau. Table 4 lists average monthly and annual snowfall total for the various stations. Table 5 list median frost dates, respectively for four different temperature thresholds. Table 6 lists the growing season (average number of days between these dates). All Zone 5 sites except Summer Lake have very short seasons (less than 2 months at 32 deg F). With such a short (and highly variable) season, it is little wonder that Zone 5 is not a major Oregon agricultural area.

Table 7 and 8 list average monthly and annual heating and growing degree days, respectively.

Climate Division 7 -- South Central Oregon

South Central Oregon, the largest of the Oregon climatic divisions, is a vast area of high desert prairie punctuated by a number of mountain ranges and isolated peaks. This region is predominantly livestock country; in addition to beef cattle, there are large numbers of sheep, dairy herds, horses, and swine. There are large amounts of land under irrigation as well, particularly in the Deschutes, Crook, Jefferson, and Klamath Counties. Among the major field crops grown are potatoes, alfalfa and other hay crops, mint, wheat, oats, barley, and onions. In the remaining counties comprising this zone (Grant, Harney, and Lake), irrigated acreage is much smaller; grazing lands and dry land farming predominate.

Figure 1 shows NOAA climate stations in Zone 7, which were in operation during the 1961-1990 period. Figure 2 shows the Lake County region from the Oregon annual precipitation map. Most of this region receives relatively low amounts of precipitation. As can be seen in Table 1, most of the stations in Zone 7 receive less than 15 inches per year. However, some of the higher mountain sites receive significantly greater precipitation. For example, Steens Mountain in Harney County, whose summit is more than 9,000 feet above sea level, receives more than 40 inches per year at its higher elevations. Other mountainous locations are also known to receive high annual amounts. Most of the stations in Zone 7 receive their highest monthly precipitation in the winter months with a secondary maximum during late spring and early summer. For other locations, the precipitation is greatest during spring and summer. Stations near the Cascades (such as Sisters, Bend, Chiloquin, Klamath Falls, and Madras) tend to have annual distributions very similar to those in western Oregon: winter maximum are followed by a steady decrease, with lowest monthly averages in midsummer. Farther east, however, spring-summer peaks are much more pronounced. At Hart Mountain, for example, the four wettest months are March through June. The months of July through September are generally the driest of the year throughout the region. These months are characterized by isolated local thunderstorms. Some months are very wet and others almost completely dry.

Table 2 lists the average number of days with precipitation amounts exceeding certain thresholds.

Table 3 lists normal monthly temperatures for Zone 7 measurement stations. Summers are generally quite warm, although the relatively high elevations tend to moderate the temperatures somewhat. Pelton Dam and Dayville, with mean maximum temperatures in the 90's during the warmest summer months, are the hottest stations in this region. The coldest sites listed are Brothers, Hart Mountain, Sprague River, and Ochoco Ranger Station. It is certain that some of the higher elevations are colder than the areas listed here, however.

Table 4 lists average monthly and annual snowfall total for the various stations.

Tables 5 and 6 list median frost dates and mean growing seasons, respectively, for four different temperature thresholds.

Table 7 and 8 list average monthly and annual heating and growing degree days, respectively.

County Description

Established: October 24, 1874
Population: 7,500
Area: 8,359 sq. mi.
Economy: Livestock, forest products, agriculture, recreation.
County Seat: Lakeview

Lake County was created from Jackson and Wasco Counties by the 1874 Legislature. It then included the present Klamath County and all of the present Lake County except Warner Valley. In 1882 Klamath was removed and in 1885 the Warner area from Grant County was added. Linkville, now Klamath Falls, was the first county seat. M. Bullard gave 20 acres as the Lakeview townsite. By the 1875 election a town had been started there and the county seat was moved to Lakeview. The Hart Mountain Antelope Refuge is a 270,000 acre wildlife haven for antelope, mule deer, bighorn sheep and upland birds. A number of migratory waterfowl flyways converge on Goose Lake, south of Lakeview, the Warner Wetlands near Plush, and the Summer Lake Wildlife area. Lakeview has been deemed the hang gliding capital of the West.

(County information obtained from Oregon Blue Book)

Climate Tables (Lake County, Oregon)


Table 1. Precipitation, Monthly and Annual Averages (1971-2000) (back to top)
Name
Number Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Adel 1 S
36 0.89 0.97 0.93 0.93 0.83 0.66 0.38 0.38 0.48 0.63 1.14 0.96 9.18
Alkali Lake
118 0.52 0.46 0.79 0.89 1.14 0.85 0.61 0.66 0.53 0.69 0.67 0.59 8.40
Hart Mountain Refuge
3692 0.92 0.91 1.42 1.54 1.69 1.17 0.46 0.50 0.79 1.06 1.20 1.06 12.72
Lakeview 2 NNW
4670 1.90 1.69 1.70 1.30 1.46 0.99 0.48 0.42 0.77 1.02 1.83 1.90 15.46
Paisley
6426 1.29 0.98 1.09 0.87 1.00 0.91 0.54 0.58 0.6 0.63 1.16 1.16 10.81
Silver Lake Ranger Stn
7817 0.99 0.73 0.81 0.76 1.11 0.79 0.58 0.59 0.57 0.61 1.10 1.16 9.80

Table 2. Average number of Days with Selected Precipitation Amounts, Lakeview 2 NNW, 1971-2000 (back to top)
Threshold
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
.01"or more
11.6 10.6 11.3 9.5 8.5 5.8 3.1 2.6 4.0 6.0 10.7 10.7 94.8
.10"or more
5.5 5.6 5.5 3.9 4.6 3.0 1.4 1.2 1.9 3.3 5.8 6.0 48.2
.50"or more
0.9 0.6 0.7 0.5 0.6 0.4 0.2 0.2 0.4 0.3 0.7 0.7 6.4
1.00"or more
0.1 0.1 0 0.1 0.1 0.1 0 0 0.1 0 0.2 0.1 0.8


Table 3. Monthly and Annual Average Temperatures (deg F), Lakeview 2 NNW (1862), 1971-2000 (back to top)
Parameter
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean max
37.8 42.0 47.9 55.8 64.6 74.0 83.8 83.1 75.1 62.7 46.0 38.6 59.3
Mean min
20.6 24.0 27.8 31.6 37.6 44.1 50.3 48.4 41.8 33.1 26.0 20.6 33.8
Mean temp
29.2 33.0 37.9 43.7 51.1 59.1 67.1 65.8 58.5 47.9 36.0 29.6 46.6
Extreme max
59 69 72 87 96 101 100 102 98 89 72 62 100
Extreme min
-14 -9 -4 12 17 26 30 26 21 9 -5 -20 -20
Mean number of days
Max 90 or more
0 0 0 0 0.1 1.1 8.4 6.5 1.3 0 0 0 16.9
Min 32 or less
27.7 24.6 23.8 17.7 8.4 1.7 0.1 0.1 3.2 14.5 24.1 28.0 175
Max 32 or less
6.5 2.8 0.7 0 0 0 0 0 0 0.1 1.5 6.1 19.2
Min 0 or less
1.5 0.9 0.1 0 0 0 0 0 0 0 0.3 1.5 5.2

Table 4. Snowfall, Monthly and Annual Averages (1971-2000) (back to top)
Name
Number Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Adel 1 S
36 3.9 4.0 3.0 1.2 0.8 0 0 0 0.1 0.4 2.5 4.2 26.3
Alkali Lake
118 2.5 1.9 1.7 1.4 0.7 0.1 0 0 0 0.3 2.2 3.9 19.9
Hart Mountain Refuge
3692 6.6 8.1 9.1 3.9 2.3 0.5 0 0 0.6 2.0 5.5 6.9 53.5
Lakeview 2 NNW
4670 10.7 11.1 6.1 4.3 1.3 0.1 0 0 0.2 1.4 8.8 11.6 67.7
Paisley
6426 2.4 3.0 2.7 1.0 0.5 0 0 0 0 0.2 1.8 3.8 16.9
Silver Lake Ranger Stn
7817 4.5 3.6 2.6 1.3 0.5 0 0 0 0 0.2 2.0 5.8 19.7

Table 5. Median Spring and Fall Frost Dates, Lakeview 2 NNW, 1971-2000 (back to top)
Percentile
Last Date in Spring of Low Temperatures (deg F)
First Date in Fall of Low Temperatures (deg F)
24
28
32
36
24
28
32
36
10
12-Apr
5-May
22-May
19-Jun
24-Sep
17-Sep
4-Sep
9-Aug
20
16-Apr
10-May
26-May
24-Jun
4-Oct
24-Sep
9-Sep
18-Aug
50
28-Apr
24-May
11-Jun
1-Jul
16-Oct
5-Oct
19-Sep
1-Sep
80
13-May
3-Jun
27-Jun
11-Jul
30-Oct
15-Oct
29-Sep
15-Sep
90
19-May
9-Jun
2-Jul
19-Jul
4-Nov
22-Oct
4-Oct
20-Sep


Table 6. Average Growing Season, Lakeview 2 NNW, 1971-2000 (back to top)
Percentile
Length of Time (Days) Between Occurrence of Temperatures ( deg F)
24
28
32
36
10
139
112
67
31
20
147
119
77
46
50
170
135
101
58
80
194
148
118
77
90
202
164
131
91


Table 7. Monthly and Annual Average Heating Degree Days (base 65°F), 1971-2000 (back to top)
Name
Number Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Adel 1 S
36 1017 810 776 577 333 126 26 35 180 445 776 993 5796
Alkali Lake
118 1067 866 817 624 409 188 58 67 231 545 847 1078 6833
Hart Mountain Refuge
3692 1098 941 930 737 536 303 126 135 322 598 915 1116 7751
Lakeview 2 NNW
4670 1110 907 840 644 438 207 55 75 216 523 881 1095 7066
Paisley
6426 1009 823 764 567 361 169 52 60 208 489 814 1030 6356
Silver Lake Ranger Stn
7817 1071 897 849 663 468 251 106 104 275 566 861 1121 7214


Table 8. Monthly and Annual Average Growing Degree Days (base 50°F), 1971-2000 (back to top)
Name
Number Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Adel 1 S
36 0 1 6 47 196 399 635 589 325 128 8 0 2334
Alkali Lake
118 0 1 5 35 135 313 531 494 253 63 3 0 1833
Hart Mountain Refuge
3692 0 0 1 13 67 186 382 373 180 47 2 0 1251
Lakeview 2 NNW
4670 0 0 1 24 116 283 529 485 275 74 1 0 1788
Paisley
6426 0 2 7 50 166 322 523 505 279 87 5 0 1946
Silver Lake Ranger Stn
7817 0 0 1 24 101 234 424 427 212 54 3 0 1480