Klamath Falls
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Klamath Falls clear sky chart from 2005-11-06 to 2024-11-02.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	7% 8% 2 5% 4 3 4 3 4 6% 55%	101436
	Night	8% 8% 2 6% 4 4 4 3 5% 6% 51%	97691
Transparency	Day	31% 5% 9% 19% 21% 14%	101183
	Night	34% 6% 11% 21% 17% 10%	97533
Seeing	Day	12% 12% 22% 24% 21% 9%	14868
	Night	11% 6% 19% 37% 24% 2	23953

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	11% 18% 6% 10% 6% 6% 5% 4 5% 6% 23%	2539
	11th to 20th	Day	20% 21% 5% 9% 4 3 3 3 4 5% 21%	2581
	21st to end	Day	19% 13% 3 9% 5% 4 4 4 6% 7% 28%	3146
February	1st to 10th	Day	8% 12% 3 9% 5% 5% 5% 4 6% 9% 35%	1710
	11th to 20th	Day	8% 13% 3 8% 6% 5% 4 5% 5% 8% 36%	1681
	21st to end	Day	8% 15% 4 8% 5% 5% 5% 4 5% 6% 33%	1570
March	1st to 10th	Day	10% 19% 5% 9% 7% 5% 5% 3 4 6% 27%	3252
	11th to 20th	Day	7% 11% 2 5% 4 3 3 2 4 6% 52%	3490
	21st to end	Day	11% 16% 3 9% 6% 6% 5% 4 6% 7% 27%	3944
April	1st to 10th	Day	9% 13% 3 8% 6% 6% 4 4 4 6% 35%	2280
	11th to 20th	Day	9% 11% 3 6% 5% 4 4 4 5% 7% 41%	2249
	21st to end	Day	6% 8% 3 6% 4 4 3 4 6% 9% 48%	2305
May	1st to 10th	Day	6% 10% 2 4 4 4 3 3 4 5% 55%	4265
	11th to 20th	Day	5% 4 1 3 2 2 3 2 4 6% 68%	4377
	21st to end	Day	5% 5% 2 4 3 4 4 3 4 7% 58%	4813
June	1st to 10th	Day	9% 5% 2 5% 4 3 4 3 7% 7% 51%	2660
	11th to 20th	Day	3 3 1 4 3 3 4 2 4 6% 66%	2660
	21st to end	Day	4 2 1 2 2 2 3 2 3 5% 73%	2660
July	1st to 10th	Day	1 1 1 1 1 1 2 1 2 2 87%	4420
	11th to 20th	Day	2 2 1 2 2 2 2 2 3 4 78%	4420
	21st to end	Day	1 1 1 1 1 2 1 2 4 85%	4683
August	1st to 10th	Day	3 2 1 3 2 2 3 3 4 5% 72%	4091
	11th to 20th	Day	1 1 2 2 2 2 3 3 5% 80%	3970
	21st to end	Day	2 2 1 2 2 2 2 2 3 3 79%	4180
September	1st to 10th	Day	1 1 2 2 2 3 2 3 4 80%	2280
	11th to 20th	Day	4 3 1 4 2 3 4 3 4 6% 66%	2280
	21st to end	Day	4 3 1 4 3 2 2 3 4 7% 66%	2024
October	1st to 10th	Day	6% 4 2 4 3 4 3 3 3 6% 63%	1900
	11th to 20th	Day	7% 4 2 4 4 4 5% 4 6% 9% 53%	1900
	21st to end	Day	9% 7% 3 6% 4 4 5% 4 5% 6% 49%	2075
November	1st to 10th	Day	12% 10% 2 7% 6% 4 4 4 5% 8% 39%	1683
	11th to 20th	Day	9% 11% 3 8% 5% 6% 5% 5% 6% 9% 32%	1586
	21st to end	Day	9% 13% 3 8% 4 3 5% 5% 5% 8% 38%	1520
December	1st to 10th	Day	10% 12% 4 8% 6% 5% 4 4 6% 7% 36%	1520
	11th to 20th	Day	16% 14% 4 8% 6% 5% 6% 4 6% 8% 22%	1928
	21st to end	Day	13% 13% 6% 11% 8% 6% 6% 4 6% 7% 20%	2794
January	1st to 10th	Night	9% 15% 5% 9% 6% 8% 6% 5% 6% 7% 24%	4406
	11th to 20th	Night	16% 18% 4 8% 4 4 4 4 4 5% 28%	4375
	21st to end	Night	18% 15% 4 9% 5% 4 4 3 5% 5% 27%	4521
February	1st to 10th	Night	9% 10% 3 6% 4 5% 5% 4 6% 7% 39%	2470
	11th to 20th	Night	10% 12% 3 6% 5% 5% 5% 3 5% 5% 40%	2384
	21st to end	Night	7% 11% 4 8% 6% 5% 4 4 5% 8% 37%	1884
March	1st to 10th	Night	10% 16% 4 8% 5% 4 4 4 6% 7% 31%	3617
	11th to 20th	Night	8% 11% 2 4 3 3 3 3 4 6% 53%	3490
	21st to end	Night	8% 15% 4 9% 6% 6% 6% 5% 6% 7% 28%	3707
April	1st to 10th	Night	10% 11% 3 8% 5% 5% 5% 4 5% 7% 38%	1900
	11th to 20th	Night	6% 9% 3 6% 5% 4 4 3 5% 7% 47%	1879
	21st to end	Night	8% 7% 2 6% 4 4 4 3 5% 8% 49%	1872
May	1st to 10th	Night	8% 8% 2 4 3 3 3 3 4 5% 57%	2685
	11th to 20th	Night	4 3 1 3 2 3 3 2 4 5% 70%	2516
	21st to end	Night	4 4 1 3 2 2 2 3 4 6% 69%	2762
June	1st to 10th	Night	9% 6% 2 5% 3 3 4 3 6% 7% 51%	1520
	11th to 20th	Night	5% 3 1 3 2 2 2 3 4 5% 70%	1520
	21st to end	Night	4 3 2 2 2 1 2 2 3 4 76%	1520
July	1st to 10th	Night	1 1 1 1 1 1 1 3 3 87%	2540
	11th to 20th	Night	2 1 1 2 2 2 2 2 3 3 79%	2540
	21st to end	Night	1 1 1 1 2 2 2 3 3 82%	2854
August	1st to 10th	Night	3 2 1 3 2 2 3 3 4 5% 73%	2848
	11th to 20th	Night	1 1 2 2 2 3 2 2 4 80%	2868
	21st to end	Night	5% 2 1 2 1 1 1 1 2 3 80%	3498
September	1st to 10th	Night	1 1 2 1 1 1 1 3 4 84%	1900
	11th to 20th	Night	4 2 1 3 2 2 2 3 5% 7% 68%	1900
	21st to end	Night	5% 3 1 3 2 2 2 2 3 6% 70%	2152
October	1st to 10th	Night	5% 3 1 3 2 3 3 3 4 6% 67%	2280
	11th to 20th	Night	7% 4 1 4 3 3 3 3 4 6% 60%	2280
	21st to end	Night	9% 5% 1 4 3 4 4 3 6% 8% 52%	2522
November	1st to 10th	Night	12% 9% 2 7% 5% 4 5% 4 5% 6% 41%	2430
	11th to 20th	Night	12% 9% 2 6% 5% 5% 5% 4 6% 8% 35%	2593
	21st to end	Night	7% 11% 4 6% 5% 5% 4 4 5% 8% 42%	2660
December	1st to 10th	Night	12% 10% 3 7% 4 4 4 3 6% 7% 41%	2660
	11th to 20th	Night	16% 13% 4 7% 6% 5% 5% 5% 6% 7% 27%	3276
	21st to end	Night	12% 12% 3 10% 7% 6% 6% 5% 5% 6% 27%	4862

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	60% 7% 13% 15% 4	2539
	11th to 20th	Day	65% 7% 7% 13% 5% 3	2581
	21st to end	Day	55% 7% 15% 16% 6% 2	3146
February	1st to 10th	Day	45% 8% 14% 20% 10% 1	1710
	11th to 20th	Day	46% 5% 15% 20% 11% 2	1690
	21st to end	Day	50% 7% 12% 16% 11% 3	1570
March	1st to 10th	Day	56% 7% 8% 21% 7% 1	3252
	11th to 20th	Day	35% 4 13% 25% 23%	3490
	21st to end	Day	54% 9% 12% 17% 7% 1	3944
April	1st to 10th	Day	49% 7% 11% 18% 12% 3	2280
	11th to 20th	Day	42% 5% 14% 22% 13% 4	2252
	21st to end	Day	33% 7% 15% 25% 18% 2	2305
May	1st to 10th	Day	31% 5% 10% 27% 24% 3	4265
	11th to 20th	Day	20% 4 7% 20% 38% 12%	4380
	21st to end	Day	25% 6% 13% 35% 18% 2	4814
June	1st to 10th	Day	31% 6% 13% 28% 19% 3	2660
	11th to 20th	Day	19% 5% 9% 29% 29% 9%	2660
	21st to end	Day	16% 3 6% 24% 33% 19%	2660
July	1st to 10th	Day	7% 1 3 12% 18% 59%	4351
	11th to 20th	Day	12% 2 3 12% 19% 52%	4345
	21st to end	Day	8% 1 2 12% 38% 38%	4535
August	1st to 10th	Day	16% 2 4 11% 27% 39%	4076
	11th to 20th	Day	9% 3 3 20% 42% 23%	4009
	21st to end	Day	12% 3 4 22% 32% 26%	4179
September	1st to 10th	Day	10% 2 4 14% 33% 36%	2280
	11th to 20th	Day	19% 5% 8% 20% 32% 16%	2280
	21st to end	Day	19% 3 9% 24% 26% 18%	2024
October	1st to 10th	Day	24% 4 11% 18% 26% 17%	1900
	11th to 20th	Day	28% 5% 13% 24% 22% 8%	1900
	21st to end	Day	36% 6% 11% 20% 20% 7%	2075
November	1st to 10th	Day	44% 7% 11% 21% 14% 3	1683
	11th to 20th	Day	48% 8% 16% 14% 13% 1	1586
	21st to end	Day	44% 8% 14% 15% 16% 3	1520
December	1st to 10th	Day	47% 8% 13% 18% 12% 2	1520
	11th to 20th	Day	58% 7% 15% 15% 5%	1928
	21st to end	Day	62% 8% 12% 13% 4	2794
January	1st to 10th	Night	56% 11% 15% 12% 5% 1	4406
	11th to 20th	Night	58% 9% 9% 14% 7% 3	4375
	21st to end	Night	58% 5% 12% 15% 8% 1	4521
February	1st to 10th	Night	43% 7% 14% 22% 12% 1	2470
	11th to 20th	Night	44% 6% 14% 22% 13% 2	2386
	21st to end	Night	43% 8% 17% 19% 10% 3	1884
March	1st to 10th	Night	49% 7% 13% 21% 9% 1	3617
	11th to 20th	Night	33% 6% 12% 30% 19%	3490
	21st to end	Night	52% 9% 15% 16% 8% 1	3707
April	1st to 10th	Night	44% 7% 17% 19% 10% 2	1900
	11th to 20th	Night	36% 7% 17% 22% 13% 5%	1879
	21st to end	Night	33% 7% 20% 26% 12% 2	1872
May	1st to 10th	Night	30% 6% 11% 30% 19% 4	2685
	11th to 20th	Night	17% 4 9% 30% 35% 4	2516
	21st to end	Night	18% 6% 22% 42% 12% 1	2762
June	1st to 10th	Night	32% 6% 16% 29% 16% 1	1520
	11th to 20th	Night	18% 4 12% 35% 25% 6%	1520
	21st to end	Night	15% 2 8% 33% 32% 11%	1520
July	1st to 10th	Night	6% 2 5% 13% 20% 54%	2500
	11th to 20th	Night	11% 2 4 10% 25% 47%	2492
	21st to end	Night	9% 2 3 13% 37% 35%	2764
August	1st to 10th	Night	15% 3 4 16% 30% 32%	2839
	11th to 20th	Night	11% 3 4 29% 35% 19%	2895
	21st to end	Night	13% 2 7% 28% 27% 24%	3498
September	1st to 10th	Night	7% 2 3 19% 33% 36%	1900
	11th to 20th	Night	16% 5% 8% 24% 29% 17%	1900
	21st to end	Night	18% 3 8% 25% 25% 21%	2152
October	1st to 10th	Night	19% 4 12% 19% 30% 16%	2280
	11th to 20th	Night	25% 4 12% 25% 25% 9%	2280
	21st to end	Night	29% 6% 13% 23% 18% 10%	2522
November	1st to 10th	Night	43% 6% 12% 19% 16% 4	2430
	11th to 20th	Night	43% 9% 14% 18% 14% 1	2593
	21st to end	Night	40% 8% 14% 18% 16% 4	2660
December	1st to 10th	Night	42% 8% 12% 20% 16% 2	2660
	11th to 20th	Night	55% 6% 11% 19% 8% 1	3276
	21st to end	Night	57% 9% 11% 16% 7% 1	4862

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	27% 17% 22% 23% 7% 3	180
	11th to 20th	Day	26% 12% 25% 18% 13% 8%	208
	21st to end	Day	18% 13% 22% 20% 19% 9%	407
February	1st to 10th	Day	18% 15% 21% 25% 18% 4	370
	11th to 20th	Day	18% 21% 22% 19% 15% 4	373
	21st to end	Day	19% 17% 24% 25% 12% 3	382
March	1st to 10th	Day	25% 17% 27% 19% 9% 2	460
	11th to 20th	Day	19% 18% 22% 21% 17% 3	460
	21st to end	Day	23% 20% 25% 21% 9% 2	506
April	1st to 10th	Day	19% 18% 24% 22% 12% 4	460
	11th to 20th	Day	18% 19% 25% 21% 12% 5%	452
	21st to end	Day	11% 21% 27% 20% 15% 6%	460
May	1st to 10th	Day	11% 17% 30% 25% 14% 3	463
	11th to 20th	Day	17% 15% 22% 22% 16% 8%	488
	21st to end	Day	11% 14% 19% 23% 21% 11%	529
June	1st to 10th	Day	11% 14% 21% 22% 21% 11%	490
	11th to 20th	Day	7% 21% 25% 20% 22% 6%	490
	21st to end	Day	3 8% 21% 30% 25% 12%	490
July	1st to 10th	Day	3 5% 24% 31% 25% 11%	486
	11th to 20th	Day	2 2 23% 30% 30% 12%	484
	21st to end	Day	3 3 19% 29% 32% 14%	531
August	1st to 10th	Day	2 2 22% 28% 30% 17%	487
	11th to 20th	Day	3 6% 16% 28% 28% 19%	477
	21st to end	Day	3 5% 17% 28% 31% 17%	539
September	1st to 10th	Day	2 4 19% 29% 33% 13%	490
	11th to 20th	Day	7% 8% 19% 28% 24% 14%	490
	21st to end	Day	6% 10% 21% 26% 28% 9%	490
October	1st to 10th	Day	8% 11% 20% 24% 23% 14%	490
	11th to 20th	Day	12% 10% 20% 20% 26% 13%	490
	21st to end	Day	11% 14% 20% 25% 19% 11%	524
November	1st to 10th	Day	19% 12% 17% 28% 16% 8%	273
	11th to 20th	Day	14% 9% 18% 25% 28% 7%	211
	21st to end	Day	16% 13% 14% 25% 24% 7%	180
December	1st to 10th	Day	17% 13% 24% 21% 17% 8%	180
	11th to 20th	Day	23% 9% 24% 23% 16% 5%	180
	21st to end	Day	19% 11% 25% 30% 14% 1	198
January	1st to 10th	Night	16% 8% 26% 32% 16% 3	760
	11th to 20th	Night	17% 10% 20% 30% 20% 2	760
	21st to end	Night	15% 5% 21% 36% 19% 3	836
February	1st to 10th	Night	13% 7% 21% 39% 18% 1	760
	11th to 20th	Night	15% 9% 20% 35% 18% 1	744
	21st to end	Night	13% 10% 25% 38% 14% 1	628
March	1st to 10th	Night	18% 12% 24% 31% 13% 1	760
	11th to 20th	Night	15% 9% 20% 33% 21% 1	760
	21st to end	Night	16% 12% 25% 33% 14%	836
April	1st to 10th	Night	15% 11% 22% 34% 16% 1	760
	11th to 20th	Night	12% 9% 28% 32% 18% 2	751
	21st to end	Night	11% 10% 22% 35% 20% 2	732
May	1st to 10th	Night	9% 5% 25% 39% 20% 1	473
	11th to 20th	Night	7% 6% 22% 36% 27% 2	374
	21st to end	Night	9% 5% 24% 35% 26% 1	411
June	1st to 10th	Night	11% 4 18% 40% 26% 1	380
	11th to 20th	Night	6% 4 26% 44% 19% 1	380
	21st to end	Night	4 1 13% 53% 29%	380
July	1st to 10th	Night	2 1 12% 48% 36% 1	370
	11th to 20th	Night	2 1 11% 54% 31%	368
	21st to end	Night	2 6% 48% 41% 3	473
August	1st to 10th	Night	2 1 5% 42% 46% 4	567
	11th to 20th	Night	2 1 7% 43% 43% 5%	594
	21st to end	Night	3 1 14% 38% 41% 3	836
September	1st to 10th	Night	2 1 13% 43% 38% 3	760
	11th to 20th	Night	3 3 14% 34% 41% 5%	760
	21st to end	Night	6% 3 15% 36% 34% 6%	760
October	1st to 10th	Night	5% 4 16% 39% 32% 3	760
	11th to 20th	Night	8% 5% 15% 35% 33% 4	760
	21st to end	Night	10% 5% 16% 38% 25% 5%	836
November	1st to 10th	Night	14% 6% 19% 37% 20% 4	748
	11th to 20th	Night	16% 5% 21% 37% 18% 2	760
	21st to end	Night	12% 8% 18% 36% 22% 3	760
December	1st to 10th	Night	17% 5% 21% 34% 21% 3	760
	11th to 20th	Night	19% 6% 21% 36% 17% 2	760
	21st to end	Night	17% 13% 26% 34% 10% 1	836

Page generated at 2024-10-30 10:19:24. Version ac07

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