Dinosaur Point
Clear Sky Chart
History

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

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	4 3 1 3 2 2 3 2 4 6% 70%	135342
	Night	5% 3 1 3 2 3 3 3 5% 7% 66%	132795
Transparency	Day	17% 6% 8% 18% 26% 26%	130316
	Night	19% 7% 10% 18% 24% 23%	128802
Seeing	Day	6% 8% 24% 32% 23% 8%	16801
	Night	6% 5% 19% 37% 26% 6%	26227

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	7% 5% 2 6% 4 3 4 4 5% 8% 53%	3759
	11th to 20th	Day	7% 5% 2 6% 4 5% 5% 3 4 5% 55%	4100
	21st to end	Day	12% 7% 2 6% 4 4 4 4 5% 6% 44%	4510
February	1st to 10th	Day	12% 6% 2 5% 4 3 4 4 6% 7% 48%	1800
	11th to 20th	Day	8% 4 1 5% 4 4 5% 4 6% 9% 49%	1925
	21st to end	Day	10% 5% 1 5% 4 5% 4 4 6% 6% 50%	1650
March	1st to 10th	Day	7% 5% 2 7% 5% 6% 7% 6% 9% 9% 38%	4711
	11th to 20th	Day	7% 4 1 5% 3 4 4 3 6% 9% 54%	5000
	21st to end	Day	7% 4 2 6% 4 5% 5% 5% 8% 10% 45%	5678
April	1st to 10th	Day	7% 5% 2 4 4 4 4 4 6% 7% 53%	2400
	11th to 20th	Day	5% 3 1 4 4 3 3 3 6% 7% 62%	2369
	21st to end	Day	4 2 1 3 3 3 3 3 5% 7% 67%	2400
May	1st to 10th	Day	2 1 1 2 2 2 2 2 3 6% 77%	5440
	11th to 20th	Day	1 1 1 1 1 1 2 3 6% 83%	6010
	21st to end	Day	1 1 1 1 1 1 3 5% 85%	6902
June	1st to 10th	Day	1 2 1 3 1 2 2 3 4 8% 74%	2800
	11th to 20th	Day	1 1 1 1 1 1 3 6% 85%	2800
	21st to end	Day	1 1 1 1 1 1 2 2 4 86%	2800
July	1st to 10th	Day	1 1 1 2 94%	6319
	11th to 20th	Day	1 1 1 1 1 1 1 2 3 89%	6062
	21st to end	Day	1 1 1 1 2 4 90%	6402
August	1st to 10th	Day	1 1 1 1 1 1 1 3 4 87%	5744
	11th to 20th	Day	1 1 1 2 94%	5364
	21st to end	Day	1 1 1 1 1 2 4 87%	5984
September	1st to 10th	Day	1 1 1 1 1 1 1 2 3 89%	2400
	11th to 20th	Day	1 1 1 1 1 1 2 4 7% 81%	2400
	21st to end	Day	1 1 1 1 1 2 1 3 6% 81%	2162
October	1st to 10th	Day	1 1 1 2 1 2 2 2 4 5% 79%	3280
	11th to 20th	Day	2 1 1 2 1 2 2 2 3 5% 79%	3261
	21st to end	Day	2 2 1 3 3 3 4 3 5% 7% 67%	3558
November	1st to 10th	Day	5% 3 1 3 3 3 5% 3 5% 8% 60%	1958
	11th to 20th	Day	6% 5% 1 4 3 3 4 3 6% 8% 56%	1890
	21st to end	Day	7% 4 2 4 4 4 4 3 5% 8% 55%	1836
December	1st to 10th	Day	5% 5% 2 5% 4 4 3 3 5% 8% 56%	2636
	11th to 20th	Day	13% 7% 3 7% 6% 5% 5% 4 7% 9% 36%	3028
	21st to end	Day	9% 9% 3 7% 6% 5% 5% 5% 7% 9% 35%	4004
January	1st to 10th	Night	7% 5% 2 4 3 3 3 3 6% 9% 55%	6174
	11th to 20th	Night	10% 5% 2 5% 3 3 3 3 4 6% 54%	5880
	21st to end	Night	11% 5% 2 6% 4 4 4 4 6% 8% 48%	6468
February	1st to 10th	Night	12% 5% 2 5% 3 4 3 3 5% 6% 52%	2600
	11th to 20th	Night	7% 3 1 4 3 4 5% 4 6% 10% 52%	2362
	21st to end	Night	8% 4 1 4 3 4 3 3 4 8% 58%	1980
March	1st to 10th	Night	8% 4 2 6% 5% 6% 6% 5% 8% 9% 41%	5166
	11th to 20th	Night	6% 4 2 6% 4 4 4 4 5% 7% 55%	5000
	21st to end	Night	8% 4 2 4 4 4 5% 5% 7% 11% 48%	5297
April	1st to 10th	Night	6% 4 1 4 4 3 4 4 7% 7% 56%	2000
	11th to 20th	Night	3 3 1 4 3 3 3 3 5% 8% 63%	1979
	21st to end	Night	3 2 1 2 2 2 3 3 5% 10% 68%	2000
May	1st to 10th	Night	1 1 1 1 1 1 1 2 4 7% 80%	4560
	11th to 20th	Night	1 1 1 1 1 1 2 3 6% 83%	3860
	21st to end	Night	1 1 1 1 1 1 3 5% 86%	3972
June	1st to 10th	Night	1 2 1 2 2 3 2 3 5% 8% 72%	1600
	11th to 20th	Night	1 1 1 1 1 1 2 3 7% 83%	1600
	21st to end	Night	1 1 1 1 2 6% 87%	1600
July	1st to 10th	Night	1 1 3 94%	3640
	11th to 20th	Night	1 1 1 1 1 1 1 2 3 90%	3906
	21st to end	Night	1 1 1 1 3 4 87%	4472
August	1st to 10th	Night	1 1 1 1 1 2 6% 86%	4070
	11th to 20th	Night	1 1 1 1 2 3 91%	4506
	21st to end	Night	1 1 1 1 1 3 5% 86%	5015
September	1st to 10th	Night	1 1 1 1 2 1 3 6% 85%	2000
	11th to 20th	Night	2 1 1 2 1 2 2 3 8% 80%	2000
	21st to end	Night	2 1 1 2 1 2 2 2 6% 80%	2231
October	1st to 10th	Night	2 1 1 1 2 2 2 3 6% 80%	3920
	11th to 20th	Night	1 1 2 2 2 2 2 3 10% 74%	3897
	21st to end	Night	3 2 1 2 2 2 2 3 5% 7% 72%	4253
November	1st to 10th	Night	4 2 1 2 2 2 3 3 5% 9% 66%	2560
	11th to 20th	Night	6% 4 2 4 3 3 3 3 5% 9% 57%	2730
	21st to end	Night	6% 4 1 5% 5% 3 3 3 5% 7% 58%	2781
December	1st to 10th	Night	6% 3 1 4 3 3 4 3 6% 7% 60%	4588
	11th to 20th	Night	11% 7% 2 7% 5% 4 5% 4 7% 10% 38%	5176
	21st to end	Night	12% 7% 2 7% 5% 5% 6% 5% 7% 10% 34%	6952

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	28% 10% 18% 25% 15% 4	3759
	11th to 20th	Day	31% 7% 8% 11% 26% 15%	4100
	21st to end	Day	37% 9% 9% 12% 23% 10%	4510
February	1st to 10th	Day	35% 7% 9% 20% 18% 11%	1800
	11th to 20th	Day	31% 9% 13% 20% 21% 7%	1935
	21st to end	Day	34% 8% 10% 23% 19% 6%	1650
March	1st to 10th	Day	35% 14% 12% 15% 22% 2	4711
	11th to 20th	Day	27% 8% 12% 32% 14% 8%	5000
	21st to end	Day	29% 14% 17% 26% 12% 2	5678
April	1st to 10th	Day	30% 8% 13% 23% 20% 7%	2400
	11th to 20th	Day	23% 7% 13% 25% 24% 8%	2372
	21st to end	Day	18% 8% 13% 28% 27% 6%	2400
May	1st to 10th	Day	10% 5% 8% 24% 37% 16%	5440
	11th to 20th	Day	5% 3 8% 29% 43% 12%	6013
	21st to end	Day	6% 5% 9% 21% 50% 9%	6904
June	1st to 10th	Day	11% 7% 12% 23% 31% 17%	2800
	11th to 20th	Day	4 3 7% 19% 35% 31%	2800
	21st to end	Day	6% 2 3 9% 29% 50%	2800
July	1st to 10th	Day	2 1 1 4 17% 76%	6251
	11th to 20th	Day	5% 2 2 4 11% 76%	5988
	21st to end	Day	3 1 2 11% 32% 51%	6217
August	1st to 10th	Day	6% 2 3 7% 25% 57%	4184
	11th to 20th	Day	2 1 1 7% 29% 60%	3880
	21st to end	Day	4 2 2 9% 29% 54%	4311
September	1st to 10th	Day	4 3 3 10% 29% 51%	2400
	11th to 20th	Day	5% 5% 7% 20% 38% 25%	2400
	21st to end	Day	8% 3 5% 19% 39% 27%	2162
October	1st to 10th	Day	10% 3 6% 11% 25% 46%	3280
	11th to 20th	Day	10% 4 5% 22% 38% 21%	3261
	21st to end	Day	15% 4 7% 20% 36% 17%	3558
November	1st to 10th	Day	22% 7% 12% 20% 26% 13%	1958
	11th to 20th	Day	26% 7% 11% 25% 23% 7%	1890
	21st to end	Day	25% 8% 11% 19% 26% 10%	1836
December	1st to 10th	Day	27% 5% 8% 25% 28% 6%	2636
	11th to 20th	Day	39% 9% 13% 19% 16% 3	3028
	21st to end	Day	41% 12% 17% 18% 10% 2	4004
January	1st to 10th	Night	25% 10% 18% 28% 16% 3	6174
	11th to 20th	Night	30% 8% 9% 13% 28% 11%	5880
	21st to end	Night	33% 10% 8% 13% 22% 13%	6468
February	1st to 10th	Night	32% 7% 9% 20% 20% 12%	2600
	11th to 20th	Night	27% 9% 13% 20% 22% 8%	2363
	21st to end	Night	27% 8% 12% 27% 17% 8%	1980
March	1st to 10th	Night	34% 13% 12% 16% 21% 4	5166
	11th to 20th	Night	27% 10% 15% 24% 16% 8%	5000
	21st to end	Night	27% 15% 19% 23% 13% 3	5297
April	1st to 10th	Night	26% 10% 16% 23% 19% 7%	2000
	11th to 20th	Night	21% 8% 14% 26% 21% 9%	1979
	21st to end	Night	14% 10% 15% 28% 27% 7%	2000
May	1st to 10th	Night	8% 7% 11% 24% 34% 16%	4557
	11th to 20th	Night	6% 4 11% 25% 35% 19%	3860
	21st to end	Night	4 5% 12% 19% 47% 13%	3972
June	1st to 10th	Night	12% 8% 11% 19% 33% 17%	1600
	11th to 20th	Night	5% 5% 7% 16% 32% 35%	1600
	21st to end	Night	4 3 6% 10% 28% 49%	1600
July	1st to 10th	Night	1 1 2 4 13% 79%	3600
	11th to 20th	Night	4 2 2 5% 10% 78%	3857
	21st to end	Night	3 1 3 10% 30% 52%	4345
August	1st to 10th	Night	6% 3 4 8% 22% 57%	2952
	11th to 20th	Night	3 2 2 6% 26% 61%	3256
	21st to end	Night	4 2 4 9% 26% 54%	3608
September	1st to 10th	Night	4 4 4 8% 23% 57%	2000
	11th to 20th	Night	7% 5% 6% 18% 34% 30%	2000
	21st to end	Night	8% 4 6% 15% 35% 31%	2231
October	1st to 10th	Night	8% 4 5% 11% 19% 53%	3920
	11th to 20th	Night	10% 4 6% 24% 33% 23%	3897
	21st to end	Night	13% 4 6% 20% 35% 22%	4253
November	1st to 10th	Night	16% 8% 11% 22% 25% 17%	2560
	11th to 20th	Night	25% 7% 12% 20% 28% 8%	2730
	21st to end	Night	25% 7% 9% 20% 25% 13%	2781
December	1st to 10th	Night	23% 5% 8% 26% 28% 9%	4588
	11th to 20th	Night	36% 11% 15% 17% 18% 3	5176
	21st to end	Night	42% 14% 14% 18% 8% 4	6952

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	19% 13% 24% 27% 15% 3	255
	11th to 20th	Day	11% 8% 23% 29% 23% 6%	400
	21st to end	Day	9% 10% 20% 30% 26% 5%	440
February	1st to 10th	Day	17% 14% 19% 24% 21% 7%	400
	11th to 20th	Day	10% 14% 26% 30% 17% 2	482
	21st to end	Day	10% 14% 23% 34% 18% 2	414
March	1st to 10th	Day	15% 15% 25% 30% 13% 3	500
	11th to 20th	Day	15% 14% 22% 25% 18% 5%	500
	21st to end	Day	13% 16% 27% 28% 15% 2	550
April	1st to 10th	Day	10% 12% 31% 22% 19% 5%	500
	11th to 20th	Day	8% 15% 31% 26% 15% 5%	492
	21st to end	Day	3 14% 34% 25% 15% 9%	500
May	1st to 10th	Day	4 13% 32% 30% 16% 5%	503
	11th to 20th	Day	4 12% 34% 31% 17% 3	528
	21st to end	Day	2 12% 27% 35% 17% 6%	573
June	1st to 10th	Day	2 8% 32% 35% 14% 8%	530
	11th to 20th	Day	2 9% 33% 32% 20% 4	530
	21st to end	Day	1 6% 25% 36% 25% 6%	530
July	1st to 10th	Day	1 2 24% 43% 22% 8%	526
	11th to 20th	Day	1 1 21% 40% 28% 8%	524
	21st to end	Day	1 1 19% 44% 24% 11%	575
August	1st to 10th	Day	2 5% 24% 38% 22% 9%	527
	11th to 20th	Day	1 3 21% 38% 27% 10%	517
	21st to end	Day	2 15% 39% 31% 14%	583
September	1st to 10th	Day	1 4 18% 35% 27% 15%	530
	11th to 20th	Day	2 7% 25% 31% 25% 11%	530
	21st to end	Day	2 4 18% 31% 32% 12%	530
October	1st to 10th	Day	2 7% 20% 25% 32% 15%	530
	11th to 20th	Day	3 6% 16% 29% 31% 15%	530
	21st to end	Day	4 6% 17% 27% 33% 13%	583
November	1st to 10th	Day	5% 7% 17% 22% 37% 11%	434
	11th to 20th	Day	8% 4 17% 33% 29% 8%	330
	21st to end	Day	8% 3 17% 36% 34% 3	301
December	1st to 10th	Day	12% 7% 21% 28% 24% 8%	204
	11th to 20th	Day	12% 8% 23% 28% 23% 7%	200
	21st to end	Day	11% 13% 21% 31% 19% 5%	220
January	1st to 10th	Night	13% 6% 13% 38% 24% 8%	800
	11th to 20th	Night	10% 5% 12% 40% 26% 8%	800
	21st to end	Night	12% 5% 13% 37% 27% 6%	880
February	1st to 10th	Night	14% 6% 15% 34% 23% 8%	800
	11th to 20th	Night	10% 5% 19% 36% 23% 6%	784
	21st to end	Night	10% 8% 18% 42% 19% 3	660
March	1st to 10th	Night	11% 11% 21% 33% 20% 4	800
	11th to 20th	Night	9% 8% 21% 34% 23% 5%	800
	21st to end	Night	9% 9% 26% 34% 18% 3	880
April	1st to 10th	Night	8% 8% 24% 35% 22% 3	800
	11th to 20th	Night	5% 12% 30% 31% 18% 5%	791
	21st to end	Night	5% 7% 31% 32% 21% 5%	800
May	1st to 10th	Night	2 7% 30% 38% 19% 4	800
	11th to 20th	Night	3 6% 29% 41% 18% 2	508
	21st to end	Night	3 7% 32% 38% 19% 1	433
June	1st to 10th	Night	1 5% 31% 42% 19% 2	400
	11th to 20th	Night	1 6% 29% 43% 20% 2	400
	21st to end	Night	1 3 23% 47% 25% 2	400
July	1st to 10th	Night	1 3 23% 45% 28% 2	390
	11th to 20th	Night	1 14% 48% 31% 6%	497
	21st to end	Night	1 1 18% 40% 33% 7%	657
August	1st to 10th	Night	1 2 18% 45% 30% 5%	607
	11th to 20th	Night	2 23% 42% 26% 5%	792
	21st to end	Night	1 1 15% 41% 35% 6%	880
September	1st to 10th	Night	1 3 17% 36% 37% 7%	800
	11th to 20th	Night	2 4 20% 39% 28% 7%	800
	21st to end	Night	3 3 16% 35% 33% 10%	800
October	1st to 10th	Night	3 3 15% 37% 33% 9%	800
	11th to 20th	Night	3 4 14% 35% 33% 11%	800
	21st to end	Night	4 3 15% 33% 29% 17%	880
November	1st to 10th	Night	4 4 15% 33% 34% 11%	820
	11th to 20th	Night	8% 3 13% 36% 32% 8%	840
	21st to end	Night	7% 3 14% 36% 32% 8%	840
December	1st to 10th	Night	11% 5% 11% 38% 27% 8%	808
	11th to 20th	Night	15% 5% 12% 37% 26% 4	800
	21st to end	Night	13% 8% 18% 37% 22% 3	880

Page generated at 2025-11-29 22:00:51. Version ac07

Copyright © 2025 Attilla Danko.