Lost Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lost Lake clear sky chart from 2005-11-06 to 2024-11-04.

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	11% 15% 5% 9% 4 3 3 3 4 5% 37%	105408
	Night	12% 16% 5% 11% 5% 3 3 3 4 5% 33%	102280
Transparency	Day	49% 6% 9% 17% 13% 6%	105151
	Night	54% 7% 9% 15% 11% 5%	102126
Seeing	Day	22% 21% 31% 18% 6% 1	14580
	Night	21% 18% 23% 24% 11% 2	23536

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	16% 32% 9% 15% 5% 3 3 2 3 4 9%	2539
	11th to 20th	Day	20% 22% 6% 11% 5% 5% 4 3 4 4 17%	2540
	21st to end	Day	21% 24% 7% 13% 5% 3 3 2 3 5% 14%	2963
February	1st to 10th	Day	15% 21% 9% 15% 5% 3 3 3 5% 4 16%	1710
	11th to 20th	Day	11% 23% 8% 15% 6% 4 4 3 3 4 17%	1665
	21st to end	Day	11% 29% 8% 14% 5% 4 3 2 3 4 18%	1529
March	1st to 10th	Day	7% 19% 9% 17% 7% 5% 5% 4 5% 5% 18%	3200
	11th to 20th	Day	8% 22% 6% 10% 4 3 3 2 3 3 36%	3490
	21st to end	Day	12% 28% 8% 16% 6% 5% 4 2 3 2 13%	3969
April	1st to 10th	Day	15% 27% 8% 13% 5% 4 3 3 3 3 16%	2280
	11th to 20th	Day	14% 24% 6% 13% 5% 4 3 2 3 4 22%	2249
	21st to end	Day	14% 23% 6% 11% 4 4 4 3 4 5% 21%	2415
May	1st to 10th	Day	13% 21% 5% 10% 4 3 3 2 3 3 32%	4420
	11th to 20th	Day	9% 12% 3 7% 5% 3 3 4 5% 6% 43%	4377
	21st to end	Day	16% 19% 5% 12% 5% 4 4 3 4 6% 23%	4813
June	1st to 10th	Day	20% 14% 4 7% 4 4 4 3 4 5% 30%	2660
	11th to 20th	Day	16% 15% 5% 10% 5% 4 5% 4 5% 6% 26%	2660
	21st to end	Day	9% 7% 2 6% 4 3 4 3 5% 7% 50%	2660
July	1st to 10th	Day	2 3 1 2 2 2 2 2 4 5% 73%	4420
	11th to 20th	Day	4 3 1 2 2 2 2 2 3 4 77%	4420
	21st to end	Day	3 3 2 3 2 1 2 2 4 5% 73%	4790
August	1st to 10th	Day	2 3 2 5% 4 3 3 2 3 5% 68%	4228
	11th to 20th	Day	3 3 1 6% 4 4 5% 4 5% 7% 59%	4026
	21st to end	Day	7% 6% 2 6% 4 3 4 3 5% 6% 55%	4242
September	1st to 10th	Day	5% 4 2 5% 3 2 3 3 5% 6% 62%	2280
	11th to 20th	Day	10% 7% 3 7% 4 4 5% 4 5% 6% 46%	2280
	21st to end	Day	11% 9% 3 7% 4 3 4 3 4 5% 47%	2019
October	1st to 10th	Day	10% 9% 3 6% 4 3 3 3 4 5% 50%	3180
	11th to 20th	Day	10% 12% 6% 10% 5% 5% 4 3 4 7% 32%	3161
	21st to end	Day	13% 16% 10% 15% 5% 5% 4 3 5% 5% 21%	3295
November	1st to 10th	Day	18% 22% 7% 13% 5% 4 4 2 4 5% 16%	1646
	11th to 20th	Day	17% 23% 5% 13% 4 4 5% 3 5% 5% 16%	1520
	21st to end	Day	15% 21% 6% 11% 5% 4 3 3 3 5% 23%	1520
December	1st to 10th	Day	14% 19% 6% 13% 5% 4 3 3 4 5% 23%	1520
	11th to 20th	Day	16% 22% 7% 13% 5% 3 4 4 7% 6% 13%	1928
	21st to end	Day	15% 24% 6% 11% 6% 5% 4 3 4 4 16%	2794
January	1st to 10th	Night	16% 29% 8% 13% 5% 4 4 3 4 4 9%	4406
	11th to 20th	Night	20% 24% 6% 10% 5% 3 4 2 4 5% 17%	4420
	21st to end	Night	20% 20% 6% 16% 5% 4 4 3 4 5% 14%	4695
February	1st to 10th	Night	13% 20% 8% 16% 6% 4 4 3 4 4 18%	2470
	11th to 20th	Night	12% 22% 8% 15% 5% 3 3 2 4 3 22%	2402
	21st to end	Night	13% 25% 9% 13% 6% 4 3 2 3 5% 17%	1924
March	1st to 10th	Night	7% 16% 7% 18% 8% 5% 5% 4 5% 6% 19%	3660
	11th to 20th	Night	7% 18% 6% 11% 5% 3 3 2 3 3 40%	3490
	21st to end	Night	12% 28% 7% 16% 6% 5% 4 3 4 4 12%	3684
April	1st to 10th	Night	12% 27% 9% 12% 6% 4 3 3 3 4 18%	1900
	11th to 20th	Night	12% 20% 6% 12% 5% 4 4 3 5% 5% 25%	1879
	21st to end	Night	13% 23% 4 12% 5% 4 4 2 5% 5% 23%	1759
May	1st to 10th	Night	15% 24% 6% 8% 4 2 2 2 3 4 31%	2540
	11th to 20th	Night	7% 15% 4 8% 5% 3 4 3 4 5% 43%	2516
	21st to end	Night	12% 22% 3 10% 5% 3 4 3 6% 7% 25%	2762
June	1st to 10th	Night	21% 14% 3 8% 4 3 4 3 5% 4 31%	1520
	11th to 20th	Night	12% 15% 5% 10% 4 5% 4 3 4 6% 31%	1520
	21st to end	Night	8% 6% 2 6% 6% 4 4 3 4 7% 50%	1520
July	1st to 10th	Night	3 3 1 3 2 1 2 2 3 4 77%	2540
	11th to 20th	Night	2 2 1 3 3 1 2 2 3 3 75%	2540
	21st to end	Night	2 3 2 3 2 1 2 2 3 4 76%	2761
August	1st to 10th	Night	3 3 1 4 3 2 2 2 4 6% 69%	2704
	11th to 20th	Night	3 3 3 10% 5% 4 3 3 4 6% 56%	2812
	21st to end	Night	5% 7% 3 8% 3 2 3 3 3 4 58%	3434
September	1st to 10th	Night	5% 4 2 6% 3 3 3 3 5% 7% 61%	1900
	11th to 20th	Night	8% 9% 4 9% 4 3 3 3 4 5% 47%	1900
	21st to end	Night	11% 8% 3 9% 3 3 4 3 4 7% 46%	2157
October	1st to 10th	Night	10% 9% 3 6% 3 2 3 3 4 6% 51%	3800
	11th to 20th	Night	10% 11% 6% 10% 4 4 4 4 6% 7% 34%	3777
	21st to end	Night	13% 15% 9% 16% 5% 4 3 3 4 4 24%	4268
November	1st to 10th	Night	20% 19% 6% 13% 6% 4 3 3 3 5% 19%	2502
	11th to 20th	Night	18% 19% 6% 14% 5% 4 4 3 4 4 19%	2660
	21st to end	Night	12% 18% 6% 13% 5% 4 4 3 5% 4 25%	2660
December	1st to 10th	Night	14% 19% 5% 14% 7% 4 3 3 5% 4 23%	2660
	11th to 20th	Night	16% 20% 6% 14% 5% 4 4 3 5% 5% 17%	3276
	21st to end	Night	16% 22% 7% 14% 5% 4 4 3 4 5% 15%	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	83% 4 5% 6% 2	2539
	11th to 20th	Day	73% 5% 8% 9% 4 2	2540
	21st to end	Day	76% 5% 6% 8% 4 1	2963
February	1st to 10th	Day	71% 6% 10% 10% 3	1710
	11th to 20th	Day	71% 6% 7% 11% 4 1	1674
	21st to end	Day	71% 5% 8% 7% 7% 1	1529
March	1st to 10th	Day	67% 5% 11% 13% 4 1	3200
	11th to 20th	Day	55% 4 5% 28% 7%	3490
	21st to end	Day	77% 5% 7% 7% 4	3969
April	1st to 10th	Day	74% 5% 8% 11% 2	2280
	11th to 20th	Day	68% 4 9% 10% 8% 2	2252
	21st to end	Day	65% 7% 9% 11% 6% 2	2415
May	1st to 10th	Day	57% 3 10% 20% 9%	4420
	11th to 20th	Day	40% 6% 20% 24% 11%	4380
	21st to end	Day	63% 9% 14% 13% 2	4814
June	1st to 10th	Day	56% 5% 12% 17% 8% 1	2660
	11th to 20th	Day	56% 8% 14% 15% 6% 1	2660
	21st to end	Day	33% 6% 15% 28% 14% 4	2660
July	1st to 10th	Day	14% 4 8% 15% 26% 34%	4351
	11th to 20th	Day	13% 3 5% 13% 26% 41%	4345
	21st to end	Day	12% 6% 8% 22% 37% 15%	4639
August	1st to 10th	Day	20% 4 7% 20% 30% 19%	4212
	11th to 20th	Day	20% 9% 12% 37% 16% 5%	4065
	21st to end	Day	28% 7% 10% 24% 26% 6%	4241
September	1st to 10th	Day	23% 4 10% 27% 24% 12%	2280
	11th to 20th	Day	37% 7% 11% 20% 18% 7%	2280
	21st to end	Day	40% 6% 10% 23% 15% 6%	2019
October	1st to 10th	Day	35% 7% 5% 23% 25% 5%	3180
	11th to 20th	Day	49% 9% 11% 18% 12% 1	3161
	21st to end	Day	56% 14% 5% 16% 8%	3295
November	1st to 10th	Day	72% 5% 7% 12% 4	1646
	11th to 20th	Day	70% 7% 8% 10% 4 1	1520
	21st to end	Day	65% 6% 6% 11% 11% 1	1520
December	1st to 10th	Day	65% 6% 7% 14% 7% 1	1520
	11th to 20th	Day	70% 8% 10% 9% 2	1928
	21st to end	Day	73% 5% 9% 11% 2	2794
January	1st to 10th	Night	80% 7% 5% 5% 2	4406
	11th to 20th	Night	72% 5% 8% 10% 3 2	4420
	21st to end	Night	75% 6% 7% 7% 5% 1	4695
February	1st to 10th	Night	71% 6% 8% 11% 5%	2470
	11th to 20th	Night	68% 4 9% 12% 6% 1	2404
	21st to end	Night	71% 5% 6% 11% 6% 1	1924
March	1st to 10th	Night	64% 5% 14% 13% 3 1	3660
	11th to 20th	Night	51% 4 10% 25% 9% 1	3490
	21st to end	Night	77% 6% 8% 7% 2	3684
April	1st to 10th	Night	71% 6% 9% 10% 4	1900
	11th to 20th	Night	63% 5% 12% 11% 8% 3	1879
	21st to end	Night	64% 6% 11% 12% 7% 1	1759
May	1st to 10th	Night	60% 3 9% 18% 10%	2540
	11th to 20th	Night	43% 7% 16% 25% 7% 2	2516
	21st to end	Night	57% 10% 20% 10% 3	2762
June	1st to 10th	Night	56% 5% 12% 20% 7% 1	1520
	11th to 20th	Night	54% 7% 14% 18% 7% 1	1520
	21st to end	Night	33% 6% 14% 26% 16% 5%	1520
July	1st to 10th	Night	13% 4 7% 15% 29% 31%	2500
	11th to 20th	Night	14% 3 6% 14% 24% 38%	2492
	21st to end	Night	11% 6% 9% 18% 38% 19%	2674
August	1st to 10th	Night	18% 4 8% 20% 28% 23%	2696
	11th to 20th	Night	17% 17% 13% 29% 18% 5%	2839
	21st to end	Night	25% 10% 10% 24% 22% 10%	3434
September	1st to 10th	Night	22% 5% 13% 24% 23% 13%	1900
	11th to 20th	Night	39% 6% 9% 19% 15% 11%	1900
	21st to end	Night	39% 5% 12% 20% 16% 8%	2157
October	1st to 10th	Night	33% 6% 7% 22% 29% 3	3800
	11th to 20th	Night	44% 9% 13% 19% 13% 2	3777
	21st to end	Night	56% 13% 5% 14% 10% 1	4268
November	1st to 10th	Night	70% 4 6% 13% 6% 1	2502
	11th to 20th	Night	69% 6% 7% 10% 7%	2660
	21st to end	Night	63% 6% 6% 13% 11% 1	2660
December	1st to 10th	Night	66% 7% 7% 13% 8%	2660
	11th to 20th	Night	69% 9% 8% 9% 4	3276
	21st to end	Night	72% 8% 9% 7% 2	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	36% 30% 19% 11% 4	180
	11th to 20th	Day	32% 24% 29% 9% 4 1	180
	21st to end	Day	31% 24% 24% 17% 4	302
February	1st to 10th	Day	29% 32% 24% 12% 3	370
	11th to 20th	Day	32% 31% 25% 11% 1 1	365
	21st to end	Day	35% 27% 26% 11% 2	363
March	1st to 10th	Day	28% 31% 28% 8% 4	460
	11th to 20th	Day	29% 25% 27% 13% 5% 1	460
	21st to end	Day	36% 27% 23% 11% 3	506
April	1st to 10th	Day	35% 25% 23% 12% 4	460
	11th to 20th	Day	31% 30% 25% 10% 2 2	452
	21st to end	Day	30% 25% 30% 12% 2 1	460
May	1st to 10th	Day	27% 20% 31% 15% 6% 1	463
	11th to 20th	Day	25% 19% 28% 19% 6% 2	488
	21st to end	Day	25% 16% 30% 21% 6% 2	529
June	1st to 10th	Day	22% 20% 29% 20% 7% 2	490
	11th to 20th	Day	26% 24% 31% 12% 6% 1	490
	21st to end	Day	10% 17% 39% 24% 9% 1	490
July	1st to 10th	Day	6% 15% 45% 28% 5% 1	486
	11th to 20th	Day	6% 16% 43% 25% 8% 2	484
	21st to end	Day	5% 12% 41% 26% 13% 4	531
August	1st to 10th	Day	3 12% 42% 27% 11% 5%	487
	11th to 20th	Day	4 13% 36% 32% 11% 4	477
	21st to end	Day	9% 19% 37% 24% 9% 3	539
September	1st to 10th	Day	7% 17% 37% 27% 10% 2	490
	11th to 20th	Day	16% 17% 35% 25% 7% 1	490
	21st to end	Day	17% 18% 33% 23% 8% 1	490
October	1st to 10th	Day	21% 17% 31% 23% 8% 1	490
	11th to 20th	Day	24% 21% 26% 20% 8% 2	490
	21st to end	Day	32% 22% 25% 13% 6% 2	448
November	1st to 10th	Day	32% 23% 24% 17% 3	252
	11th to 20th	Day	29% 27% 24% 14% 4 2	180
	21st to end	Day	26% 25% 29% 16% 4	180
December	1st to 10th	Day	31% 20% 26% 17% 4 2	180
	11th to 20th	Day	33% 28% 28% 10% 2	180
	21st to end	Day	35% 28% 18% 15% 3 1	198
January	1st to 10th	Night	32% 24% 21% 16% 6%	760
	11th to 20th	Night	28% 21% 23% 21% 7% 1	760
	21st to end	Night	25% 19% 25% 22% 7% 1	836
February	1st to 10th	Night	24% 22% 25% 22% 7% 1	760
	11th to 20th	Night	28% 25% 18% 22% 6%	744
	21st to end	Night	29% 25% 22% 19% 4	628
March	1st to 10th	Night	23% 25% 21% 22% 9% 1	760
	11th to 20th	Night	22% 22% 24% 22% 8% 1	760
	21st to end	Night	28% 24% 23% 15% 8% 1	836
April	1st to 10th	Night	29% 19% 24% 18% 8% 1	760
	11th to 20th	Night	26% 21% 24% 17% 9% 3	751
	21st to end	Night	25% 18% 25% 21% 10% 1	619
May	1st to 10th	Night	25% 13% 23% 24% 14% 2	380
	11th to 20th	Night	18% 13% 21% 30% 16% 2	374
	21st to end	Night	17% 16% 23% 27% 16% 2	411
June	1st to 10th	Night	28% 13% 20% 24% 13% 2	380
	11th to 20th	Night	19% 18% 28% 24% 10%	380
	21st to end	Night	11% 10% 27% 33% 17% 1	380
July	1st to 10th	Night	8% 6% 30% 36% 19%	370
	11th to 20th	Night	4 8% 37% 34% 15% 2	368
	21st to end	Night	3 7% 27% 43% 18% 2	416
August	1st to 10th	Night	4 8% 24% 38% 21% 4	475
	11th to 20th	Night	5% 6% 20% 34% 26% 9%	564
	21st to end	Night	7% 10% 30% 31% 19% 4	798
September	1st to 10th	Night	8% 8% 24% 36% 21% 3	760
	11th to 20th	Night	12% 12% 21% 29% 22% 4	760
	21st to end	Night	15% 9% 24% 29% 19% 3	760
October	1st to 10th	Night	18% 13% 23% 29% 15% 4	760
	11th to 20th	Night	19% 15% 18% 27% 17% 3	760
	21st to end	Night	25% 21% 19% 20% 10% 3	836
November	1st to 10th	Night	30% 21% 19% 23% 7% 1	754
	11th to 20th	Night	29% 22% 24% 18% 5% 1	760
	21st to end	Night	20% 26% 24% 23% 7% 1	760
December	1st to 10th	Night	24% 21% 27% 20% 8% 1	760
	11th to 20th	Night	30% 22% 24% 19% 4	760
	21st to end	Night	33% 26% 23% 14% 4 1	836

Page generated at 2024-11-01 19:47:37. Version ac07

Copyright © 2024 Attilla Danko.