Astrodoc's Doghouse Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Astrodoc's Doghouse Observatory clear sky chart from 2005-11-06 to 2024-02-20.

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	15% 10% 4 8% 7% 4 5% 5% 5% 7% 30%	78794
	Night	15% 11% 5% 8% 6% 3 5% 5% 5% 7% 30%	80376
Transparency	Day	53% 7% 11% 18% 10% 1	78508
	Night	53% 6% 11% 18% 10% 1	80197
Seeing	Day	20% 14% 29% 22% 11% 4	13831
	Night	20% 13% 31% 25% 10% 1	23048

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	16% 19% 8% 12% 7% 3 4 3 3 5% 21%	2549
	11th to 20th	Day	11% 19% 9% 16% 9% 4 6% 6% 5% 4 10%	2840
	21st to end	Day	20% 19% 8% 12% 8% 5% 5% 4 4 4 12%	3124
February	1st to 10th	Day	16% 16% 6% 10% 10% 5% 6% 4 5% 5% 16%	1710
	11th to 20th	Day	14% 12% 7% 13% 8% 4 5% 5% 6% 7% 19%	1654
	21st to end	Day	18% 14% 6% 9% 8% 4 6% 4 4 6% 21%	1417
March	1st to 10th	Day	15% 12% 5% 9% 7% 4 6% 4 5% 6% 28%	1959
	11th to 20th	Day	13% 12% 5% 8% 8% 3 6% 4 4 6% 31%	1980
	21st to end	Day	18% 11% 4 8% 7% 3 5% 4 5% 6% 30%	2178
April	1st to 10th	Day	17% 13% 5% 7% 6% 3 4 4 6% 6% 28%	2088
	11th to 20th	Day	19% 10% 3 6% 4 3 5% 4 5% 6% 35%	2248
	21st to end	Day	21% 9% 4 6% 6% 4 4 4 5% 7% 32%	2340
May	1st to 10th	Day	17% 9% 3 6% 6% 3 4 5% 6% 7% 34%	2340
	11th to 20th	Day	15% 8% 3 7% 6% 3 5% 5% 6% 6% 37%	2396
	21st to end	Day	12% 5% 3 5% 6% 3 5% 5% 5% 9% 41%	2725
June	1st to 10th	Day	14% 6% 3 5% 5% 4 5% 6% 7% 9% 38%	2520
	11th to 20th	Day	12% 6% 3 6% 6% 3 5% 6% 6% 10% 40%	2613
	21st to end	Day	14% 6% 2 5% 6% 3 5% 5% 6% 8% 40%	2700
July	1st to 10th	Day	8% 4 3 5% 5% 3 5% 5% 7% 9% 45%	2678
	11th to 20th	Day	11% 6% 3 5% 6% 3 6% 6% 7% 10% 37%	2468
	21st to end	Day	11% 6% 3 6% 6% 4 5% 6% 6% 11% 37%	2547
August	1st to 10th	Day	9% 5% 2 6% 7% 4 6% 7% 7% 9% 38%	2327
	11th to 20th	Day	11% 6% 4 6% 6% 4 5% 7% 6% 9% 36%	2303
	21st to end	Day	12% 6% 3 5% 6% 4 6% 5% 6% 9% 38%	2512
September	1st to 10th	Day	12% 6% 2 6% 6% 3 5% 5% 6% 9% 39%	2160
	11th to 20th	Day	12% 5% 3 5% 5% 3 4 5% 6% 9% 43%	1998
	21st to end	Day	14% 8% 3 6% 6% 3 6% 5% 7% 8% 35%	1977
October	1st to 10th	Day	20% 8% 3 7% 5% 3 5% 5% 5% 7% 32%	1800
	11th to 20th	Day	22% 9% 4 8% 5% 4 4 4 6% 6% 28%	1800
	21st to end	Day	25% 13% 4 7% 6% 4 5% 5% 5% 6% 21%	1980
November	1st to 10th	Day	16% 11% 4 7% 6% 3 5% 5% 5% 8% 29%	1625
	11th to 20th	Day	16% 13% 5% 7% 7% 3 5% 6% 6% 6% 25%	1520
	21st to end	Day	18% 15% 8% 10% 6% 3 5% 3 6% 7% 18%	1520
December	1st to 10th	Day	15% 18% 7% 13% 7% 4 6% 5% 4 6% 14%	1520
	11th to 20th	Day	18% 17% 7% 10% 8% 4 5% 6% 4 6% 17%	1906
	21st to end	Day	28% 19% 6% 11% 8% 4 5% 4 4 3 8%	2772
January	1st to 10th	Night	17% 18% 8% 13% 7% 4 5% 4 5% 6% 15%	4396
	11th to 20th	Night	14% 14% 8% 14% 12% 6% 7% 6% 5% 5% 10%	4120
	21st to end	Night	21% 14% 9% 11% 6% 4 4 4 4 5% 17%	4532
February	1st to 10th	Night	15% 14% 6% 10% 9% 5% 5% 5% 5% 5% 20%	2470
	11th to 20th	Night	14% 12% 7% 9% 8% 3 6% 5% 6% 7% 23%	2397
	21st to end	Night	16% 12% 5% 11% 7% 4 5% 5% 5% 6% 24%	1837
March	1st to 10th	Night	13% 8% 5% 8% 7% 4 7% 5% 5% 6% 32%	1988
	11th to 20th	Night	13% 11% 5% 7% 7% 3 5% 5% 4 5% 34%	1979
	21st to end	Night	17% 11% 4 6% 6% 3 4 4 5% 5% 36%	2178
April	1st to 10th	Night	18% 10% 4 6% 6% 3 4 5% 5% 6% 33%	1870
	11th to 20th	Night	16% 10% 2 5% 5% 4 4 4 5% 6% 38%	1674
	21st to end	Night	15% 8% 3 8% 6% 3 4 4 6% 7% 35%	1620
May	1st to 10th	Night	15% 8% 3 6% 5% 3 5% 5% 5% 7% 38%	1620
	11th to 20th	Night	14% 6% 2 6% 4 3 4 4 5% 7% 43%	1495
	21st to end	Night	9% 4 2 4 4 3 5% 4 6% 9% 50%	1550
June	1st to 10th	Night	11% 5% 3 4 5% 3 5% 5% 6% 8% 44%	1440
	11th to 20th	Night	11% 5% 2 5% 4 4 5% 5% 7% 9% 43%	1341
	21st to end	Night	11% 6% 2 5% 5% 3 5% 4 5% 7% 47%	1260
July	1st to 10th	Night	5% 3 2 4 4 3 3 4 5% 10% 57%	1278
	11th to 20th	Night	9% 4 3 5% 4 2 5% 4 5% 9% 50%	1487
	21st to end	Night	8% 5% 2 4 5% 3 5% 5% 6% 9% 48%	1771
August	1st to 10th	Night	7% 5% 3 4 6% 3 4 5% 7% 8% 48%	1611
	11th to 20th	Night	6% 5% 3 4 5% 3 4 4 6% 10% 50%	1598
	21st to end	Night	11% 5% 3 5% 4 3 4 5% 6% 7% 48%	1826
September	1st to 10th	Night	10% 5% 3 5% 5% 3 5% 5% 6% 7% 47%	1800
	11th to 20th	Night	12% 5% 2 4 3 2 4 4 5% 8% 52%	1959
	21st to end	Night	15% 7% 3 6% 6% 3 4 4 5% 7% 42%	1982
October	1st to 10th	Night	15% 7% 3 8% 6% 3 4 5% 4 7% 39%	2160
	11th to 20th	Night	18% 9% 3 7% 6% 3 4 5% 4 6% 34%	2160
	21st to end	Night	22% 10% 4 7% 6% 3 5% 4 6% 7% 26%	2376
November	1st to 10th	Night	15% 9% 3 7% 5% 3 4 5% 6% 8% 35%	2449
	11th to 20th	Night	16% 12% 5% 7% 7% 4 5% 5% 5% 8% 26%	2660
	21st to end	Night	18% 13% 5% 9% 5% 3 5% 5% 5% 7% 24%	2660
December	1st to 10th	Night	19% 15% 7% 10% 7% 4 6% 5% 5% 6% 17%	2660
	11th to 20th	Night	16% 17% 7% 10% 7% 3 4 4 5% 5% 20%	3288
	21st to end	Night	27% 20% 8% 11% 7% 3 4 4 4 4 9%	4884

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	67% 6% 10% 10% 8%	2550
	11th to 20th	Day	74% 7% 8% 6% 4	2840
	21st to end	Day	75% 7% 7% 6% 4 1	3124
February	1st to 10th	Day	70% 7% 8% 11% 4 1	1710
	11th to 20th	Day	64% 5% 9% 13% 7% 2	1663
	21st to end	Day	65% 4 9% 13% 7% 1	1417
March	1st to 10th	Day	57% 6% 12% 15% 9% 1	1962
	11th to 20th	Day	55% 7% 10% 16% 11% 3	1980
	21st to end	Day	55% 5% 10% 16% 11% 2	2178
April	1st to 10th	Day	56% 6% 11% 16% 10% 1	2088
	11th to 20th	Day	50% 5% 11% 20% 13% 1	2248
	21st to end	Day	53% 6% 10% 18% 11% 2	2340
May	1st to 10th	Day	49% 6% 11% 22% 12% 1	2340
	11th to 20th	Day	46% 8% 10% 22% 12% 2	2400
	21st to end	Day	40% 7% 15% 23% 14% 2	2725
June	1st to 10th	Day	42% 8% 12% 21% 15% 1	2520
	11th to 20th	Day	39% 8% 13% 24% 15% 1	2613
	21st to end	Day	40% 8% 13% 24% 15%	2700
July	1st to 10th	Day	33% 8% 13% 25% 18% 2	2605
	11th to 20th	Day	38% 8% 17% 25% 11% 1	2393
	21st to end	Day	39% 10% 13% 22% 14% 2	2405
August	1st to 10th	Day	39% 10% 15% 24% 10% 2	2314
	11th to 20th	Day	42% 10% 15% 22% 10%	2303
	21st to end	Day	41% 7% 14% 25% 12% 1	2512
September	1st to 10th	Day	41% 8% 14% 24% 11% 1	2160
	11th to 20th	Day	36% 8% 14% 28% 13% 1	1998
	21st to end	Day	45% 9% 13% 24% 9%	1977
October	1st to 10th	Day	52% 7% 13% 16% 12% 2	1800
	11th to 20th	Day	57% 6% 12% 17% 8% 1	1800
	21st to end	Day	63% 7% 11% 14% 6%	1980
November	1st to 10th	Day	53% 7% 12% 19% 8% 1	1625
	11th to 20th	Day	57% 8% 13% 13% 8% 1	1520
	21st to end	Day	66% 5% 11% 12% 5%	1520
December	1st to 10th	Day	70% 8% 9% 9% 4	1520
	11th to 20th	Day	69% 7% 10% 9% 6%	1906
	21st to end	Day	82% 5% 6% 6% 2	2772
January	1st to 10th	Night	68% 8% 9% 10% 4 1	4396
	11th to 20th	Night	75% 7% 8% 7% 3	4120
	21st to end	Night	69% 6% 10% 11% 4 1	4532
February	1st to 10th	Night	64% 7% 9% 15% 4 1	2470
	11th to 20th	Night	60% 6% 10% 15% 9% 1	2399
	21st to end	Night	59% 5% 11% 15% 8%	1837
March	1st to 10th	Night	51% 5% 13% 19% 10% 2	1998
	11th to 20th	Night	51% 5% 10% 20% 12% 2	1980
	21st to end	Night	51% 5% 7% 19% 15% 3	2178
April	1st to 10th	Night	52% 5% 9% 18% 15% 1	1870
	11th to 20th	Night	46% 5% 9% 20% 17% 2	1674
	21st to end	Night	48% 5% 9% 20% 15% 2	1620
May	1st to 10th	Night	45% 6% 8% 22% 16% 3	1620
	11th to 20th	Night	41% 6% 11% 24% 15% 4	1496
	21st to end	Night	31% 8% 13% 27% 17% 4	1551
June	1st to 10th	Night	36% 8% 12% 26% 17% 1	1440
	11th to 20th	Night	36% 7% 12% 25% 18% 2	1341
	21st to end	Night	36% 7% 14% 25% 17% 1	1260
July	1st to 10th	Night	25% 7% 12% 28% 25% 4	1242
	11th to 20th	Night	31% 6% 13% 31% 17% 2	1439
	21st to end	Night	32% 8% 15% 26% 16% 3	1672
August	1st to 10th	Night	32% 8% 17% 30% 12% 2	1600
	11th to 20th	Night	29% 9% 14% 32% 15% 1	1598
	21st to end	Night	34% 8% 12% 29% 15% 2	1826
September	1st to 10th	Night	36% 8% 14% 27% 14% 1	1800
	11th to 20th	Night	30% 7% 12% 31% 19% 1	1959
	21st to end	Night	41% 7% 13% 27% 12% 1	1982
October	1st to 10th	Night	45% 7% 10% 22% 15% 1	2160
	11th to 20th	Night	51% 6% 13% 21% 9% 1	2160
	21st to end	Night	57% 6% 11% 17% 9%	2376
November	1st to 10th	Night	46% 6% 14% 20% 12% 1	2449
	11th to 20th	Night	55% 7% 13% 16% 7% 1	2660
	21st to end	Night	59% 7% 15% 13% 5%	2660
December	1st to 10th	Night	67% 7% 11% 11% 3	2660
	11th to 20th	Night	66% 6% 11% 13% 4	3288
	21st to end	Night	80% 6% 7% 6% 2	4884

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	25% 19% 33% 15% 6% 1	189
	11th to 20th	Day	24% 25% 34% 13% 3 1	270
	21st to end	Day	26% 22% 33% 16% 4	297
February	1st to 10th	Day	28% 25% 33% 11% 3	270
	11th to 20th	Day	24% 27% 40% 9%	267
	21st to end	Day	37% 27% 28% 7% 1	198
March	1st to 10th	Day	26% 19% 32% 18% 5%	402
	11th to 20th	Day	22% 17% 35% 20% 5% 1	420
	21st to end	Day	30% 15% 30% 18% 5% 1	462
April	1st to 10th	Day	23% 21% 31% 17% 7%	420
	11th to 20th	Day	30% 17% 25% 18% 9% 2	412
	21st to end	Day	24% 15% 35% 18% 8% 2	420
May	1st to 10th	Day	23% 13% 30% 20% 9% 5%	423
	11th to 20th	Day	18% 12% 30% 24% 12% 4	447
	21st to end	Day	15% 9% 28% 27% 14% 7%	485
June	1st to 10th	Day	14% 14% 32% 25% 12% 3	450
	11th to 20th	Day	14% 11% 28% 30% 13% 3	543
	21st to end	Day	16% 8% 32% 28% 13% 3	630
July	1st to 10th	Day	8% 6% 27% 31% 20% 8%	600
	11th to 20th	Day	14% 7% 27% 23% 20% 8%	444
	21st to end	Day	10% 6% 32% 30% 16% 7%	488
August	1st to 10th	Day	10% 7% 22% 29% 22% 10%	446
	11th to 20th	Day	13% 5% 21% 29% 21% 12%	439
	21st to end	Day	14% 7% 25% 25% 21% 8%	495
September	1st to 10th	Day	12% 11% 24% 25% 18% 10%	450
	11th to 20th	Day	11% 6% 21% 28% 21% 12%	450
	21st to end	Day	17% 16% 24% 22% 14% 7%	450
October	1st to 10th	Day	22% 15% 23% 22% 14% 5%	450
	11th to 20th	Day	24% 17% 35% 16% 7% 1	450
	21st to end	Day	32% 17% 28% 17% 5% 1	495
November	1st to 10th	Day	26% 18% 33% 14% 7%	251
	11th to 20th	Day	28% 21% 30% 16% 3 3	180
	21st to end	Day	27% 22% 35% 12% 4 1	180
December	1st to 10th	Day	33% 23% 29% 12% 4	180
	11th to 20th	Day	34% 22% 28% 14% 2 1	180
	21st to end	Day	30% 26% 33% 11% 1	198
January	1st to 10th	Night	24% 22% 34% 15% 5% 1	760
	11th to 20th	Night	28% 19% 31% 19% 3	760
	21st to end	Night	21% 15% 38% 19% 6%	836
February	1st to 10th	Night	23% 22% 32% 20% 2	760
	11th to 20th	Night	23% 19% 36% 18% 4	742
	21st to end	Night	23% 21% 37% 16% 3	592
March	1st to 10th	Night	19% 17% 38% 21% 6%	720
	11th to 20th	Night	22% 18% 36% 18% 6%	720
	21st to end	Night	22% 15% 31% 23% 8% 1	792
April	1st to 10th	Night	24% 16% 32% 23% 4	720
	11th to 20th	Night	22% 14% 31% 22% 9% 1	610
	21st to end	Night	18% 11% 34% 28% 8%	540
May	1st to 10th	Night	18% 10% 31% 26% 14% 1	540
	11th to 20th	Night	15% 6% 34% 32% 11% 1	434
	21st to end	Night	11% 6% 27% 37% 19%	389
June	1st to 10th	Night	14% 5% 32% 38% 12% 1	360
	11th to 20th	Night	12% 8% 34% 33% 13%	360
	21st to end	Night	13% 5% 29% 38% 15%	360
July	1st to 10th	Night	5% 5% 23% 45% 21% 1	350
	11th to 20th	Night	8% 4 30% 37% 20% 2	395
	21st to end	Night	11% 3 24% 42% 19% 2	591
August	1st to 10th	Night	8% 3 25% 38% 24% 3	537
	11th to 20th	Night	8% 4 18% 38% 28% 3	534
	21st to end	Night	14% 4 25% 32% 23% 3	638
September	1st to 10th	Night	12% 6% 24% 33% 20% 5%	720
	11th to 20th	Night	13% 5% 22% 32% 23% 5%	720
	21st to end	Night	19% 8% 23% 26% 19% 5%	720
October	1st to 10th	Night	19% 9% 28% 25% 16% 3	720
	11th to 20th	Night	22% 13% 29% 26% 9% 1	720
	21st to end	Night	26% 16% 31% 23% 5%	792
November	1st to 10th	Night	22% 13% 30% 25% 9% 1	740
	11th to 20th	Night	23% 18% 32% 19% 7% 1	760
	21st to end	Night	26% 19% 32% 18% 4 1	760
December	1st to 10th	Night	28% 20% 30% 17% 4	760
	11th to 20th	Night	26% 20% 36% 14% 3	760
	21st to end	Night	31% 18% 33% 16% 2	836

Page generated at 2024-02-17 06:28:35. Version ac07

Copyright 2024 Attilla Danko