Lookout Point
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lookout Point clear sky chart from 2005-11-06 to 2026-01-02.

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	16% 10% 3 9% 5% 5% 5% 4 5% 7% 32%	127697
	Night	16% 12% 4 10% 5% 5% 4 3 5% 6% 29%	123658
Transparency	Day	52% 5% 11% 21% 10% 1	131201
	Night	55% 4 11% 19% 10% 1	128241
Seeing	Day	23% 14% 29% 21% 10% 3	15773
	Night	23% 11% 27% 28% 11% 1	24977

By Month

Percentage Cloud Cover NE (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	14% 17% 6% 17% 8% 5% 4 3 3 4 19%	3605
	11th to 20th	Day	11% 16% 6% 16% 9% 6% 5% 3 4 5% 19%	3570
	21st to end	Day	11% 18% 7% 15% 7% 5% 4 3 5% 5% 21%	4235
February	1st to 10th	Day	12% 16% 5% 13% 8% 5% 5% 4 5% 6% 21%	1800
	11th to 20th	Day	13% 16% 5% 11% 6% 5% 5% 3 5% 6% 26%	1753
	21st to end	Day	18% 14% 4 10% 6% 5% 4 4 5% 6% 25%	1597
March	1st to 10th	Day	20% 13% 4 11% 5% 4 5% 3 5% 5% 25%	4610
	11th to 20th	Day	12% 13% 4 10% 6% 5% 5% 4 5% 7% 28%	4980
	21st to end	Day	17% 11% 3 8% 5% 4 3 3 4 4 38%	5681
April	1st to 10th	Day	22% 12% 3 6% 5% 4 4 3 4 6% 31%	2400
	11th to 20th	Day	23% 10% 2 7% 4 4 3 4 4 5% 35%	2374
	21st to end	Day	22% 10% 3 7% 5% 4 4 3 4 5% 33%	2575
May	1st to 10th	Day	21% 9% 3 7% 5% 5% 4 4 6% 6% 31%	6346
	11th to 20th	Day	16% 8% 3 7% 5% 4 5% 4 6% 8% 35%	6318
	21st to end	Day	19% 8% 3 7% 5% 4 5% 3 5% 6% 34%	6949
June	1st to 10th	Day	20% 8% 3 8% 5% 4 5% 4 5% 6% 31%	2800
	11th to 20th	Day	14% 5% 2 6% 4 6% 5% 4 5% 9% 39%	2800
	21st to end	Day	16% 7% 3 7% 5% 5% 5% 5% 6% 8% 33%	2800
July	1st to 10th	Day	13% 6% 2 7% 6% 5% 6% 5% 7% 9% 34%	6360
	11th to 20th	Day	10% 5% 2 6% 4 5% 5% 4 6% 7% 44%	6360
	21st to end	Day	9% 5% 2 5% 4 4 5% 4 7% 10% 46%	6926
August	1st to 10th	Day	12% 6% 3 8% 6% 6% 6% 4 7% 8% 35%	4405
	11th to 20th	Day	16% 6% 2 7% 5% 5% 4 4 7% 8% 36%	4174
	21st to end	Day	11% 5% 2 6% 4 5% 6% 5% 7% 10% 39%	4355
September	1st to 10th	Day	14% 6% 3 6% 4 4 4 4 6% 8% 42%	2400
	11th to 20th	Day	12% 6% 3 6% 4 4 5% 3 5% 7% 45%	2400
	21st to end	Day	18% 6% 3 7% 4 5% 5% 4 6% 7% 36%	2110
October	1st to 10th	Day	20% 8% 2 7% 4 5% 5% 3 5% 6% 35%	2000
	11th to 20th	Day	24% 11% 3 8% 5% 5% 4 4 4 5% 27%	2000
	21st to end	Day	26% 11% 3 8% 5% 4 5% 2 5% 6% 25%	2081
November	1st to 10th	Day	17% 12% 4 7% 5% 5% 4 4 5% 6% 32%	1779
	11th to 20th	Day	18% 14% 5% 11% 6% 5% 5% 3 4 5% 23%	1680
	21st to end	Day	24% 17% 5% 10% 7% 5% 5% 3 4 5% 15%	1680
December	1st to 10th	Day	19% 21% 6% 11% 7% 6% 5% 3 4 4 13%	2680
	11th to 20th	Day	16% 17% 6% 13% 6% 6% 4 3 3 5% 22%	3066
	21st to end	Day	22% 19% 5% 14% 4 4 4 2 3 4 19%	4048
January	1st to 10th	Night	14% 21% 8% 16% 6% 4 4 2 3 4 17%	6364
	11th to 20th	Night	12% 14% 6% 15% 8% 6% 6% 4 5% 5% 20%	6315
	21st to end	Night	11% 19% 8% 14% 7% 7% 4 3 4 5% 19%	6720
February	1st to 10th	Night	13% 15% 5% 15% 7% 5% 5% 4 5% 6% 22%	2600
	11th to 20th	Night	13% 16% 5% 12% 7% 5% 4 3 5% 5% 26%	2533
	21st to end	Night	15% 15% 4 12% 6% 5% 4 3 4 6% 27%	2032
March	1st to 10th	Night	19% 16% 4 9% 5% 4 4 3 3 4 28%	5226
	11th to 20th	Night	13% 13% 4 9% 4 5% 5% 4 7% 8% 27%	4979
	21st to end	Night	16% 10% 4 11% 6% 4 4 3 4 6% 31%	5250
April	1st to 10th	Night	20% 12% 3 8% 5% 5% 5% 3 5% 6% 30%	2000
	11th to 20th	Night	19% 11% 3 7% 4 4 4 4 4 6% 35%	1975
	21st to end	Night	21% 9% 3 8% 5% 4 4 3 5% 6% 31%	1840
May	1st to 10th	Night	23% 9% 3 7% 4 5% 4 4 6% 7% 28%	3594
	11th to 20th	Night	15% 7% 2 7% 5% 5% 5% 3 6% 7% 40%	3575
	21st to end	Night	18% 9% 3 8% 5% 4 5% 4 6% 6% 33%	3926
June	1st to 10th	Night	17% 7% 3 8% 5% 4 5% 4 6% 7% 36%	1600
	11th to 20th	Night	14% 6% 3 5% 4 4 4 4 5% 8% 43%	1600
	21st to end	Night	17% 8% 2 6% 6% 5% 5% 3 5% 7% 36%	1600
July	1st to 10th	Night	14% 6% 3 7% 6% 5% 6% 5% 7% 7% 35%	3600
	11th to 20th	Night	12% 6% 2 7% 4 5% 4 4 6% 7% 43%	3600
	21st to end	Night	8% 5% 2 5% 5% 4 5% 3 7% 8% 49%	3926
August	1st to 10th	Night	11% 6% 2 6% 5% 5% 6% 4 8% 8% 40%	2740
	11th to 20th	Night	16% 6% 2 6% 4 4 4 3 5% 8% 40%	2875
	21st to end	Night	13% 5% 2 6% 5% 4 5% 4 6% 7% 41%	3510
September	1st to 10th	Night	11% 6% 2 6% 5% 5% 4 3 5% 8% 45%	2000
	11th to 20th	Night	15% 5% 2 6% 3 2 3 3 5% 7% 48%	2000
	21st to end	Night	18% 7% 3 7% 4 4 4 3 3 6% 42%	2287
October	1st to 10th	Night	19% 8% 2 5% 4 4 4 3 4 6% 41%	2400
	11th to 20th	Night	22% 11% 3 7% 6% 4 4 3 5% 5% 29%	2400
	21st to end	Night	23% 12% 3 8% 4 5% 4 3 5% 6% 27%	2758
November	1st to 10th	Night	19% 12% 3 7% 5% 4 4 4 5% 6% 30%	2735
	11th to 20th	Night	18% 14% 4 9% 6% 5% 4 3 4 6% 26%	2940
	21st to end	Night	22% 17% 5% 11% 5% 5% 4 3 4 6% 19%	2940
December	1st to 10th	Night	19% 20% 6% 12% 7% 5% 4 4 5% 5% 14%	4720
	11th to 20th	Night	21% 17% 5% 11% 5% 4 3 2 4 5% 23%	5348
	21st to end	Night	25% 19% 4 11% 5% 3 4 2 3 4 20%	7150

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	71% 3 8% 12% 6%	3606
	11th to 20th	Day	69% 3 9% 11% 8%	3600
	21st to end	Day	67% 4 8% 13% 7% 1	4235
February	1st to 10th	Day	64% 4 9% 17% 6% 1	1800
	11th to 20th	Day	60% 3 12% 15% 9% 1	1762
	21st to end	Day	61% 4 10% 15% 10% 2	1597
March	1st to 10th	Day	61% 3 8% 12% 13% 2	4613
	11th to 20th	Day	55% 4 15% 15% 9% 1	4980
	21st to end	Day	51% 3 7% 21% 17% 2	5681
April	1st to 10th	Day	54% 3 7% 20% 13% 3	2400
	11th to 20th	Day	52% 4 6% 21% 15% 2	2374
	21st to end	Day	54% 3 7% 17% 15% 4	2575
May	1st to 10th	Day	52% 6% 8% 21% 10% 4	6357
	11th to 20th	Day	46% 6% 12% 22% 12% 1	6322
	21st to end	Day	51% 5% 11% 19% 13% 2	6949
June	1st to 10th	Day	52% 5% 9% 20% 13% 1	2800
	11th to 20th	Day	42% 5% 12% 25% 14% 2	2800
	21st to end	Day	47% 7% 12% 21% 12% 1	2800
July	1st to 10th	Day	44% 6% 14% 27% 9%	6290
	11th to 20th	Day	36% 6% 13% 33% 11%	6285
	21st to end	Day	32% 5% 16% 37% 10%	6728
August	1st to 10th	Day	46% 6% 15% 24% 9%	4391
	11th to 20th	Day	43% 6% 17% 26% 7%	4213
	21st to end	Day	37% 6% 16% 29% 11% 1	4355
September	1st to 10th	Day	40% 6% 14% 29% 11%	2400
	11th to 20th	Day	39% 5% 11% 33% 11% 1	2400
	21st to end	Day	47% 5% 14% 24% 10%	2110
October	1st to 10th	Day	51% 4 10% 27% 7%	3260
	11th to 20th	Day	53% 5% 12% 24% 6%	3240
	21st to end	Day	55% 4 18% 18% 4 1	3345
November	1st to 10th	Day	52% 5% 14% 22% 6% 1	1779
	11th to 20th	Day	61% 5% 13% 13% 7% 1	1680
	21st to end	Day	72% 4 10% 8% 5%	1680
December	1st to 10th	Day	76% 4 9% 9% 2	2680
	11th to 20th	Day	66% 4 7% 15% 8%	3066
	21st to end	Day	71% 3 7% 15% 4	4048
January	1st to 10th	Night	73% 3 10% 11% 3	6364
	11th to 20th	Night	67% 4 11% 13% 5%	6360
	21st to end	Night	68% 3 7% 10% 11% 1	6720
February	1st to 10th	Night	64% 4 10% 15% 7% 1	2600
	11th to 20th	Night	61% 4 9% 19% 7% 1	2535
	21st to end	Night	59% 3 9% 19% 9% 1	2032
March	1st to 10th	Night	61% 3 9% 14% 11% 3	5236
	11th to 20th	Night	53% 7% 16% 15% 8% 2	4980
	21st to end	Night	54% 4 7% 20% 12% 3	5250
April	1st to 10th	Night	56% 4 8% 18% 12% 2	2000
	11th to 20th	Night	50% 4 7% 22% 15% 2	1975
	21st to end	Night	55% 3 7% 17% 16% 2	1840
May	1st to 10th	Night	54% 6% 8% 20% 9% 4	3600
	11th to 20th	Night	42% 7% 13% 20% 15% 3	3576
	21st to end	Night	50% 5% 12% 18% 13% 1	3927
June	1st to 10th	Night	46% 6% 12% 25% 10% 1	1600
	11th to 20th	Night	39% 6% 11% 27% 16% 2	1600
	21st to end	Night	47% 5% 12% 22% 14% 1	1600
July	1st to 10th	Night	45% 6% 15% 22% 11% 1	3560
	11th to 20th	Night	38% 5% 13% 32% 12%	3552
	21st to end	Night	33% 5% 11% 38% 13%	3809
August	1st to 10th	Night	40% 7% 14% 27% 13%	2730
	11th to 20th	Night	41% 6% 16% 28% 9%	2902
	21st to end	Night	40% 6% 15% 26% 11% 2	3510
September	1st to 10th	Night	39% 5% 12% 30% 14% 1	2000
	11th to 20th	Night	36% 4 16% 34% 10% 1	2000
	21st to end	Night	44% 4 13% 28% 11%	2287
October	1st to 10th	Night	41% 4 13% 30% 12%	3920
	11th to 20th	Night	50% 4 15% 22% 8%	3899
	21st to end	Night	53% 5% 17% 17% 7%	4444
November	1st to 10th	Night	54% 5% 13% 20% 8%	2735
	11th to 20th	Night	60% 4 12% 15% 8% 1	2940
	21st to end	Night	67% 4 11% 14% 3	2940
December	1st to 10th	Night	73% 4 10% 11% 3	4720
	11th to 20th	Night	66% 3 8% 13% 10%	5348
	21st to end	Night	70% 3 6% 12% 9%	7150

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	22% 16% 33% 23% 5%	202
	11th to 20th	Day	28% 18% 34% 17% 4 1	200
	21st to end	Day	22% 19% 32% 20% 6% 1	280
February	1st to 10th	Day	29% 20% 34% 13% 4	300
	11th to 20th	Day	25% 27% 36% 10% 1	300
	21st to end	Day	30% 18% 35% 16% 1	361
March	1st to 10th	Day	27% 18% 33% 18% 4 1	500
	11th to 20th	Day	24% 19% 33% 18% 5% 1	500
	21st to end	Day	30% 18% 29% 17% 6% 1	550
April	1st to 10th	Day	33% 19% 26% 15% 8%	500
	11th to 20th	Day	34% 16% 22% 15% 10% 3	492
	21st to end	Day	30% 16% 31% 15% 6% 2	500
May	1st to 10th	Day	26% 14% 29% 21% 7% 3	503
	11th to 20th	Day	20% 17% 31% 19% 9% 4	527
	21st to end	Day	21% 15% 29% 21% 11% 2	573
June	1st to 10th	Day	24% 11% 30% 22% 11% 1	530
	11th to 20th	Day	17% 13% 28% 25% 14% 4	530
	21st to end	Day	19% 13% 31% 21% 13% 2	530
July	1st to 10th	Day	12% 6% 27% 35% 16% 3	525
	11th to 20th	Day	13% 8% 31% 29% 15% 4	524
	21st to end	Day	13% 7% 32% 29% 15% 4	576
August	1st to 10th	Day	13% 7% 23% 31% 19% 6%	526
	11th to 20th	Day	15% 6% 22% 28% 20% 9%	519
	21st to end	Day	13% 10% 27% 26% 18% 7%	583
September	1st to 10th	Day	17% 8% 27% 23% 16% 8%	530
	11th to 20th	Day	14% 8% 21% 22% 20% 16%	530
	21st to end	Day	18% 10% 28% 21% 15% 7%	530
October	1st to 10th	Day	24% 13% 22% 21% 15% 5%	530
	11th to 20th	Day	28% 17% 31% 16% 7% 1	530
	21st to end	Day	29% 15% 25% 23% 5% 1	517
November	1st to 10th	Day	29% 17% 31% 16% 7% 1	353
	11th to 20th	Day	23% 20% 37% 12% 6% 1	220
	21st to end	Day	35% 19% 31% 9% 4 2	220
December	1st to 10th	Day	28% 13% 39% 16% 3	220
	11th to 20th	Day	26% 25% 33% 12% 4	220
	21st to end	Day	30% 16% 32% 14% 7% 1	242
January	1st to 10th	Night	28% 13% 33% 21% 5%	805
	11th to 20th	Night	28% 15% 26% 24% 8% 1	800
	21st to end	Night	19% 12% 33% 27% 8%	880
February	1st to 10th	Night	20% 14% 37% 24% 5% 1	800
	11th to 20th	Night	23% 14% 37% 21% 5%	783
	21st to end	Night	23% 16% 29% 27% 5%	660
March	1st to 10th	Night	25% 15% 31% 25% 5%	800
	11th to 20th	Night	24% 16% 33% 22% 6%	800
	21st to end	Night	22% 15% 31% 25% 8%	880
April	1st to 10th	Night	26% 14% 28% 25% 7%	800
	11th to 20th	Night	26% 14% 29% 23% 9%	791
	21st to end	Night	24% 15% 27% 25% 9% 1	640
May	1st to 10th	Night	23% 8% 29% 30% 10% 1	400
	11th to 20th	Night	21% 10% 27% 34% 8%	394
	21st to end	Night	16% 6% 33% 33% 12%	433
June	1st to 10th	Night	18% 8% 27% 39% 9%	400
	11th to 20th	Night	16% 7% 27% 38% 13% 1	400
	21st to end	Night	21% 6% 23% 36% 14% 1	400
July	1st to 10th	Night	11% 4 25% 43% 17% 1	390
	11th to 20th	Night	14% 4 20% 43% 18% 1	388
	21st to end	Night	10% 3 23% 46% 18% 1	438
August	1st to 10th	Night	11% 3 19% 39% 27% 1	487
	11th to 20th	Night	14% 4 15% 38% 27% 4	594
	21st to end	Night	14% 5% 22% 36% 20% 2	830
September	1st to 10th	Night	14% 5% 25% 34% 20% 2	800
	11th to 20th	Night	18% 5% 18% 31% 24% 4	800
	21st to end	Night	21% 8% 20% 30% 20% 2	800
October	1st to 10th	Night	23% 7% 25% 29% 15% 2	800
	11th to 20th	Night	28% 10% 29% 22% 10% 1	800
	21st to end	Night	28% 12% 26% 27% 6%	880
November	1st to 10th	Night	26% 14% 24% 27% 8% 1	820
	11th to 20th	Night	25% 16% 30% 19% 9% 1	840
	21st to end	Night	34% 14% 25% 22% 6%	840
December	1st to 10th	Night	31% 14% 29% 20% 6%	840
	11th to 20th	Night	28% 16% 28% 23% 5% 1	840
	21st to end	Night	34% 12% 27% 22% 5%	924

Page generated at 2025-12-30 01:14:10. Version ac07

Copyright © 2025 Attilla Danko.