Indian Pass Penninsula
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Indian Pass Penninsula clear sky chart from 2005-11-06 to 2025-03-12.

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	9% 5% 2 6% 4 4 5% 4 7% 10% 44%	109266
	Night	9% 5% 2 5% 4 4 4 4 6% 9% 47%	109756
Transparency	Day	19% 45% 10% 12% 10% 4	113188
	Night	20% 43% 10% 12% 11% 5%	113972
Seeing	Day	11% 7% 22% 27% 21% 12%	15295
	Night	10% 6% 18% 28% 28% 10%	25367

By Month

Percentage Cloud Cover SE (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% 6% 2 4 4 3 5% 3 4 7% 51%	4056
	11th to 20th	Day	14% 7% 2 6% 4 4 4 4 6% 8% 43%	4363
	21st to end	Day	13% 7% 2 6% 4 3 4 3 6% 8% 43%	4972
February	1st to 10th	Day	15% 6% 2 7% 4 4 4 3 5% 7% 43%	2000
	11th to 20th	Day	15% 5% 2 5% 3 3 4 3 5% 7% 48%	1948
	21st to end	Day	13% 6% 2 5% 4 4 4 3 6% 6% 47%	1650
March	1st to 10th	Day	17% 7% 2 7% 4 4 4 3 6% 8% 39%	3271
	11th to 20th	Day	7% 4 2 6% 4 4 5% 4 7% 9% 48%	3491
	21st to end	Day	15% 5% 2 4 3 3 3 3 5% 8% 49%	3815
April	1st to 10th	Day	10% 5% 2 5% 4 4 5% 4 7% 8% 46%	2166
	11th to 20th	Day	9% 5% 2 6% 4 4 3 3 5% 7% 50%	2254
	21st to end	Day	5% 3 1 3 4 3 4 3 5% 9% 60%	2280
May	1st to 10th	Day	5% 4 1 4 3 3 4 4 6% 9% 55%	4018
	11th to 20th	Day	9% 5% 2 7% 4 4 5% 4 6% 8% 46%	4081
	21st to end	Day	4 2 1 3 3 4 4 4 6% 11% 58%	4476
June	1st to 10th	Day	8% 6% 2 6% 5% 5% 5% 5% 9% 11% 37%	2470
	11th to 20th	Day	6% 4 2 6% 5% 5% 6% 5% 9% 12% 40%	2470
	21st to end	Day	7% 5% 2 6% 6% 7% 7% 7% 8% 12% 34%	2470
July	1st to 10th	Day	6% 4 2 6% 6% 6% 7% 8% 12% 16% 28%	4120
	11th to 20th	Day	6% 4 2 6% 5% 6% 6% 5% 9% 12% 39%	4120
	21st to end	Day	3 4 2 7% 7% 7% 8% 6% 11% 16% 29%	4287
August	1st to 10th	Day	6% 4 2 6% 4 6% 6% 6% 10% 15% 36%	3785
	11th to 20th	Day	6% 3 2 5% 4 5% 5% 5% 9% 11% 43%	3729
	21st to end	Day	5% 4 2 5% 5% 6% 7% 6% 10% 17% 32%	4180
September	1st to 10th	Day	9% 6% 2 7% 5% 5% 6% 6% 9% 14% 29%	2104
	11th to 20th	Day	9% 4 3 7% 5% 5% 7% 5% 9% 10% 35%	2090
	21st to end	Day	10% 4 2 5% 5% 4 4 4 7% 9% 46%	2090
October	1st to 10th	Day	9% 5% 2 6% 4 4 5% 4 5% 8% 47%	2090
	11th to 20th	Day	6% 3 1 3 3 3 3 3 5% 7% 63%	2090
	21st to end	Day	7% 5% 2 5% 4 4 4 3 5% 6% 56%	2123
November	1st to 10th	Day	8% 3 2 4 3 3 3 4 5% 7% 56%	1838
	11th to 20th	Day	9% 4 2 5% 4 3 4 4 5% 8% 54%	1800
	21st to end	Day	8% 6% 2 6% 4 4 5% 4 6% 7% 49%	1800
December	1st to 10th	Day	8% 6% 2 5% 3 3 4 4 4 7% 54%	2930
	11th to 20th	Day	10% 7% 2 5% 3 3 4 3 4 6% 51%	3373
	21st to end	Day	15% 9% 3 6% 3 3 5% 4 5% 6% 42%	4466
January	1st to 10th	Night	10% 6% 2 5% 3 3 3 3 5% 7% 52%	5889
	11th to 20th	Night	15% 8% 3 7% 5% 4 4 4 6% 8% 36%	5581
	21st to end	Night	15% 8% 2 5% 3 4 4 4 7% 9% 39%	5984
February	1st to 10th	Night	13% 7% 3 5% 4 4 4 3 5% 7% 46%	2400
	11th to 20th	Night	14% 7% 3 5% 4 4 3 2 4 6% 48%	2338
	21st to end	Night	12% 7% 2 6% 4 4 4 3 5% 6% 47%	1980
March	1st to 10th	Night	16% 10% 3 8% 4 4 4 4 5% 6% 35%	3800
	11th to 20th	Night	8% 5% 2 5% 4 4 5% 5% 7% 9% 47%	3498
	21st to end	Night	15% 6% 1 5% 3 4 3 3 5% 7% 49%	3817
April	1st to 10th	Night	8% 5% 2 5% 4 4 4 4 7% 9% 48%	2028
	11th to 20th	Night	9% 4 3 6% 3 4 4 5% 6% 8% 49%	1875
	21st to end	Night	4 4 1 4 3 4 4 3 5% 8% 59%	1900
May	1st to 10th	Night	5% 4 2 4 3 3 3 3 6% 10% 57%	2876
	11th to 20th	Night	9% 5% 2 6% 5% 4 5% 5% 6% 8% 47%	2812
	21st to end	Night	4 3 1 4 3 4 4 4 7% 11% 57%	3079
June	1st to 10th	Night	5% 5% 2 7% 4 5% 5% 5% 8% 9% 43%	1710
	11th to 20th	Night	5% 4 1 5% 4 5% 5% 4 8% 12% 48%	1710
	21st to end	Night	5% 4 2 6% 5% 5% 5% 4 7% 13% 44%	1710
July	1st to 10th	Night	4 4 2 5% 5% 5% 5% 6% 10% 17% 36%	2840
	11th to 20th	Night	2 3 1 4 3 3 4 5% 9% 13% 52%	2840
	21st to end	Night	2 2 1 4 5% 5% 7% 6% 11% 17% 39%	3262
August	1st to 10th	Night	5% 2 1 4 3 4 5% 5% 10% 14% 47%	3144
	11th to 20th	Night	4 3 2 4 4 5% 4 5% 9% 13% 48%	3100
	21st to end	Night	6% 3 2 5% 5% 5% 7% 6% 11% 15% 37%	3476
September	1st to 10th	Night	7% 6% 3 6% 5% 5% 6% 5% 8% 12% 36%	2057
	11th to 20th	Night	9% 6% 2 8% 5% 5% 6% 5% 8% 11% 35%	2090
	21st to end	Night	8% 5% 2 5% 4 4 5% 5% 6% 9% 48%	2090
October	1st to 10th	Night	6% 4 2 5% 5% 5% 4 5% 6% 9% 49%	2090
	11th to 20th	Night	6% 4 1 4 3 3 4 3 5% 8% 60%	2090
	21st to end	Night	8% 5% 2 5% 4 4 5% 4 5% 7% 52%	2473
November	1st to 10th	Night	7% 3 2 5% 5% 4 4 3 6% 7% 54%	2455
	11th to 20th	Night	10% 5% 2 5% 4 4 4 3 6% 6% 52%	2600
	21st to end	Night	10% 6% 2 6% 4 4 4 3 5% 6% 51%	2600
December	1st to 10th	Night	8% 5% 2 5% 3 3 4 3 5% 7% 55%	4250
	11th to 20th	Night	11% 5% 2 4 3 3 3 3 5% 7% 54%	4822
	21st to end	Night	14% 8% 3 6% 5% 4 4 4 4 6% 43%	6490

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	24% 28% 6% 11% 23% 8%	4057
	11th to 20th	Day	32% 28% 3 11% 15% 10%	4363
	21st to end	Day	26% 30% 7% 14% 18% 6%	4972
February	1st to 10th	Day	15% 62% 4 7% 7% 4	2000
	11th to 20th	Day	14% 61% 3 11% 9% 3	1958
	21st to end	Day	15% 62% 5% 6% 8% 4	1650
March	1st to 10th	Day	32% 42% 7% 11% 5% 2	3271
	11th to 20th	Day	20% 44% 12% 9% 12% 3	3491
	21st to end	Day	22% 41% 6% 16% 8% 7%	3815
April	1st to 10th	Day	13% 66% 5% 6% 6% 4	2166
	11th to 20th	Day	13% 66% 3 8% 7% 2	2254
	21st to end	Day	9% 66% 5% 10% 7% 4	2280
May	1st to 10th	Day	15% 45% 10% 16% 11% 3	4055
	11th to 20th	Day	23% 43% 8% 16% 10% 1	4085
	21st to end	Day	9% 42% 15% 24% 9% 1	4489
June	1st to 10th	Day	16% 66% 8% 8% 2	2470
	11th to 20th	Day	14% 67% 8% 8% 4	2470
	21st to end	Day	13% 66% 10% 8% 3	2470
July	1st to 10th	Day	21% 41% 32% 5%	4055
	11th to 20th	Day	19% 40% 35% 5%	4051
	21st to end	Day	25% 45% 24% 6%	4150
August	1st to 10th	Day	21% 40% 16% 16% 7% 1	3773
	11th to 20th	Day	14% 40% 18% 20% 7% 1	3765
	21st to end	Day	19% 42% 24% 11% 4	4179
September	1st to 10th	Day	17% 63% 10% 5% 3 1	2104
	11th to 20th	Day	15% 63% 7% 10% 5% 1	2090
	21st to end	Day	13% 62% 8% 11% 4 2	2090
October	1st to 10th	Day	31% 38% 5% 7% 11% 8%	3480
	11th to 20th	Day	4 36% 1 15% 22% 21%	3458
	21st to end	Day	8% 37% 3 15% 30% 8%	3473
November	1st to 10th	Day	16% 57% 5% 9% 8% 5%	1838
	11th to 20th	Day	16% 57% 5% 5% 12% 5%	1800
	21st to end	Day	14% 57% 4 11% 10% 5%	1800
December	1st to 10th	Day	20% 35% 8% 12% 17% 8%	2930
	11th to 20th	Day	21% 32% 5% 15% 19% 9%	3370
	21st to end	Day	33% 29% 6% 12% 18% 2	4466
January	1st to 10th	Night	24% 26% 5% 12% 22% 11%	5889
	11th to 20th	Night	39% 27% 4 12% 13% 5%	5581
	21st to end	Night	29% 29% 9% 13% 15% 6%	5984
February	1st to 10th	Night	16% 62% 3 8% 9% 3	2400
	11th to 20th	Night	15% 60% 4 8% 10% 3	2339
	21st to end	Night	15% 62% 5% 6% 7% 5%	1980
March	1st to 10th	Night	37% 42% 6% 9% 5% 2	3800
	11th to 20th	Night	20% 43% 9% 12% 11% 4	3498
	21st to end	Night	25% 41% 5% 12% 10% 7%	3817
April	1st to 10th	Night	13% 66% 5% 5% 7% 5%	2028
	11th to 20th	Night	12% 65% 2 9% 8% 4	1875
	21st to end	Night	9% 65% 3 10% 10% 3	1900
May	1st to 10th	Night	13% 44% 15% 15% 9% 4	2904
	11th to 20th	Night	22% 44% 9% 15% 9% 1	2813
	21st to end	Night	10% 41% 10% 30% 8% 1	3087
June	1st to 10th	Night	13% 66% 9% 9% 3	1710
	11th to 20th	Night	12% 67% 9% 8% 3 1	1710
	21st to end	Night	10% 65% 12% 9% 4	1710
July	1st to 10th	Night	18% 40% 34% 8%	2795
	11th to 20th	Night	10% 43% 39% 7% 1	2786
	21st to end	Night	18% 47% 27% 7% 1	3158
August	1st to 10th	Night	15% 39% 18% 18% 10%	3132
	11th to 20th	Night	12% 40% 19% 24% 5%	3130
	21st to end	Night	17% 42% 24% 10% 6%	3476
September	1st to 10th	Night	17% 62% 10% 6% 4 2	2057
	11th to 20th	Night	15% 62% 10% 8% 5%	2090
	21st to end	Night	11% 61% 9% 12% 6% 1	2090
October	1st to 10th	Night	31% 38% 6% 8% 11% 6%	3480
	11th to 20th	Night	5% 36% 2 14% 21% 21%	3461
	21st to end	Night	9% 36% 3 13% 31% 8%	4073
November	1st to 10th	Night	18% 56% 5% 10% 7% 4	2455
	11th to 20th	Night	18% 57% 2 8% 9% 5%	2600
	21st to end	Night	14% 57% 4 9% 10% 6%	2600
December	1st to 10th	Night	20% 36% 6% 11% 15% 12%	4250
	11th to 20th	Night	19% 32% 8% 16% 16% 9%	4824
	21st to end	Night	33% 28% 6% 14% 16% 3	6490

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	12% 19% 45% 20% 4	300
	11th to 20th	Day	16% 15% 35% 26% 8%	300
	21st to end	Day	18% 22% 45% 14% 2	330
February	1st to 10th	Day	17% 11% 46% 21% 5% 1	300
	11th to 20th	Day	21% 14% 39% 20% 5%	300
	21st to end	Day	12% 12% 51% 20% 5%	249
March	1st to 10th	Day	16% 17% 42% 22% 3	325
	11th to 20th	Day	12% 12% 35% 28% 11% 1	464
	21st to end	Day	12% 11% 36% 26% 13% 1	506
April	1st to 10th	Day	14% 14% 31% 27% 12% 2	460
	11th to 20th	Day	14% 11% 30% 27% 16% 3	452
	21st to end	Day	8% 8% 29% 34% 18% 3	460
May	1st to 10th	Day	7% 6% 28% 32% 21% 7%	463
	11th to 20th	Day	8% 4 20% 33% 22% 13%	487
	21st to end	Day	6% 2 14% 31% 29% 17%	529
June	1st to 10th	Day	11% 3 12% 32% 23% 19%	490
	11th to 20th	Day	8% 3 12% 24% 29% 24%	490
	21st to end	Day	7% 2 8% 28% 31% 24%	490
July	1st to 10th	Day	8% 4 5% 16% 32% 36%	485
	11th to 20th	Day	8% 2 1 14% 37% 38%	484
	21st to end	Day	5% 2 4 20% 38% 31%	532
August	1st to 10th	Day	8% 3 4 21% 34% 30%	486
	11th to 20th	Day	9% 2 3 16% 38% 32%	479
	21st to end	Day	7% 4 8% 24% 33% 23%	539
September	1st to 10th	Day	12% 3 5% 28% 30% 23%	490
	11th to 20th	Day	12% 3 10% 32% 29% 14%	490
	21st to end	Day	9% 2 10% 29% 34% 15%	490
October	1st to 10th	Day	11% 4 23% 36% 19% 6%	490
	11th to 20th	Day	5% 7% 18% 37% 27% 7%	490
	21st to end	Day	9% 5% 24% 41% 19% 3	539
November	1st to 10th	Day	11% 5% 25% 42% 14% 4	376
	11th to 20th	Day	10% 10% 33% 37% 9% 1	300
	21st to end	Day	11% 10% 37% 30% 10% 2	300
December	1st to 10th	Day	14% 14% 36% 24% 10% 2	300
	11th to 20th	Day	17% 12% 37% 27% 7%	300
	21st to end	Day	17% 11% 36% 27% 7% 1	330
January	1st to 10th	Night	16% 13% 31% 28% 11% 1	800
	11th to 20th	Night	14% 11% 27% 33% 14% 1	800
	21st to end	Night	18% 11% 33% 29% 9% 1	880
February	1st to 10th	Night	16% 10% 26% 33% 14% 1	800
	11th to 20th	Night	17% 9% 31% 30% 12% 1	783
	21st to end	Night	16% 9% 29% 36% 10%	660
March	1st to 10th	Night	13% 7% 27% 39% 14% 1	800
	11th to 20th	Night	11% 7% 25% 34% 22% 1	767
	21st to end	Night	11% 7% 27% 34% 21% 1	836
April	1st to 10th	Night	10% 6% 25% 36% 21% 2	698
	11th to 20th	Night	11% 6% 20% 36% 25% 1	563
	21st to end	Night	5% 4 22% 34% 32% 2	570
May	1st to 10th	Night	5% 4 16% 36% 32% 7%	570
	11th to 20th	Night	7% 2 16% 31% 36% 8%	561
	21st to end	Night	5% 2 6% 28% 49% 10%	617
June	1st to 10th	Night	8% 2 5% 24% 47% 14%	570
	11th to 20th	Night	5% 2 5% 20% 44% 24%	570
	21st to end	Night	7% 1 4 14% 49% 24%	570
July	1st to 10th	Night	7% 2 2 11% 43% 36%	555
	11th to 20th	Night	5% 1 1 8% 42% 43%	552
	21st to end	Night	3 1 1 10% 50% 35%	624
August	1st to 10th	Night	5% 1 1 8% 46% 39%	567
	11th to 20th	Night	5% 1 2 10% 41% 41%	564
	21st to end	Night	10% 2 4 15% 44% 25%	627
September	1st to 10th	Night	9% 2 5% 17% 44% 23%	727
	11th to 20th	Night	10% 3 6% 24% 41% 14%	760
	21st to end	Night	10% 1 8% 27% 41% 13%	760
October	1st to 10th	Night	7% 4 18% 34% 30% 7%	760
	11th to 20th	Night	6% 5% 16% 32% 34% 7%	760
	21st to end	Night	10% 5% 17% 37% 28% 3	836
November	1st to 10th	Night	8% 5% 19% 40% 25% 3	780
	11th to 20th	Night	11% 7% 26% 31% 23% 2	800
	21st to end	Night	11% 9% 23% 37% 18% 2	800
December	1st to 10th	Night	12% 8% 26% 32% 19% 3	800
	11th to 20th	Night	15% 7% 29% 33% 15% 1	800
	21st to end	Night	18% 8% 28% 32% 14%	880

Page generated at 2025-03-09 08:08:48. Version ac07

Copyright © 2025 Attilla Danko.