Mahoney State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mahoney State Park clear sky chart from 2005-11-06 to 2024-11-03.

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	11% 7% 3 7% 4 4 4 4 5% 7% 44%	101035
	Night	10% 7% 2 6% 4 3 4 3 5% 7% 48%	98025
Transparency	Day	38% 7% 14% 25% 15% 2	100848
	Night	35% 6% 13% 26% 17% 3	97883
Seeing	Day	13% 9% 30% 30% 15% 3	15792
	Night	13% 8% 33% 34% 11% 1	25634

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% 13% 5% 14% 8% 6% 4 3 4 6% 27%	2847
	11th to 20th	Day	9% 11% 5% 11% 4 4 6% 4 4 6% 36%	2850
	21st to end	Day	8% 13% 6% 13% 6% 5% 4 3 4 5% 32%	3135
February	1st to 10th	Day	10% 12% 5% 9% 6% 5% 4 3 6% 7% 34%	1710
	11th to 20th	Day	10% 9% 2 9% 5% 3 5% 4 5% 8% 40%	1707
	21st to end	Day	11% 8% 3 6% 4 5% 4 3 6% 7% 44%	1570
March	1st to 10th	Day	12% 9% 3 6% 3 3 3 2 3 5% 50%	3377
	11th to 20th	Day	11% 8% 3 5% 4 3 3 3 4 5% 50%	3480
	21st to end	Day	19% 12% 4 9% 4 4 5% 4 5% 7% 28%	3814
April	1st to 10th	Day	15% 9% 2 6% 4 3 4 3 4 6% 44%	2137
	11th to 20th	Day	15% 9% 3 6% 4 4 4 4 4 6% 40%	2371
	21st to end	Day	19% 7% 3 5% 4 4 4 3 5% 7% 38%	2470
May	1st to 10th	Day	15% 8% 3 7% 5% 4 5% 4 6% 7% 36%	4082
	11th to 20th	Day	13% 8% 3 7% 4 3 4 3 5% 6% 44%	4082
	21st to end	Day	13% 6% 3 6% 5% 5% 5% 4 6% 7% 40%	4538
June	1st to 10th	Day	7% 5% 2 4 4 4 5% 5% 6% 9% 49%	2660
	11th to 20th	Day	9% 5% 2 5% 4 4 4 4 7% 8% 47%	2660
	21st to end	Day	6% 5% 2 5% 5% 5% 4 4 6% 8% 50%	2650
July	1st to 10th	Day	11% 6% 2 6% 4 4 5% 4 6% 8% 45%	4120
	11th to 20th	Day	7% 4 2 5% 4 4 4 3 6% 8% 53%	4120
	21st to end	Day	4 3 1 4 4 4 4 4 7% 10% 54%	4465
August	1st to 10th	Day	6% 4 2 5% 4 5% 5% 5% 7% 11% 46%	4104
	11th to 20th	Day	12% 6% 2 6% 4 4 5% 4 6% 8% 42%	4041
	21st to end	Day	6% 5% 2 7% 4 4 5% 4 5% 8% 51%	4468
September	1st to 10th	Day	12% 5% 2 5% 3 3 3 3 4 6% 54%	2193
	11th to 20th	Day	10% 5% 2 5% 3 4 3 3 5% 7% 54%	2090
	21st to end	Day	10% 4 1 4 3 3 3 3 4 6% 58%	2090
October	1st to 10th	Day	13% 6% 2 4 3 3 3 3 4 6% 52%	1952
	11th to 20th	Day	11% 6% 1 5% 4 3 3 3 3 4 57%	1900
	21st to end	Day	12% 8% 2 6% 3 3 4 3 5% 6% 47%	2090
November	1st to 10th	Day	9% 7% 2 4 3 3 4 3 5% 6% 55%	1707
	11th to 20th	Day	9% 6% 3 8% 5% 4 4 3 4 5% 48%	1677
	21st to end	Day	12% 10% 3 5% 4 3 3 4 5% 7% 45%	1520
December	1st to 10th	Day	8% 8% 3 6% 5% 4 3 4 5% 7% 46%	1520
	11th to 20th	Day	8% 10% 4 9% 5% 5% 4 3 7% 6% 39%	1918
	21st to end	Day	15% 12% 6% 14% 5% 4 4 3 4 6% 26%	2920
January	1st to 10th	Night	8% 11% 3 17% 8% 6% 4 4 5% 6% 29%	4108
	11th to 20th	Night	8% 10% 3 8% 4 4 7% 5% 7% 7% 37%	4120
	21st to end	Night	11% 13% 6% 10% 4 4 4 3 5% 6% 34%	4532
February	1st to 10th	Night	10% 11% 4 8% 6% 4 5% 4 5% 5% 39%	2470
	11th to 20th	Night	8% 8% 3 7% 5% 4 5% 4 6% 7% 43%	2375
	21st to end	Night	10% 8% 2 6% 3 4 3 3 5% 6% 50%	1884
March	1st to 10th	Night	11% 6% 2 6% 4 3 2 3 4 5% 53%	3467
	11th to 20th	Night	11% 7% 2 5% 2 2 3 3 4 5% 57%	3480
	21st to end	Night	18% 10% 3 8% 4 4 4 4 6% 7% 33%	3817
April	1st to 10th	Night	12% 8% 2 5% 4 4 3 3 5% 6% 47%	2043
	11th to 20th	Night	11% 8% 2 6% 4 3 4 3 5% 8% 47%	1755
	21st to end	Night	17% 7% 2 6% 3 3 3 3 4 5% 46%	1710
May	1st to 10th	Night	18% 7% 2 4 4 4 3 3 5% 6% 44%	2823
	11th to 20th	Night	12% 5% 2 5% 4 4 3 3 5% 7% 50%	2823
	21st to end	Night	15% 7% 2 5% 4 3 3 4 5% 7% 44%	3011
June	1st to 10th	Night	5% 4 2 4 5% 4 4 4 6% 8% 54%	1520
	11th to 20th	Night	7% 4 2 4 3 4 4 5% 8% 10% 50%	1520
	21st to end	Night	4 3 1 4 3 4 4 4 7% 9% 57%	1524
July	1st to 10th	Night	7% 6% 2 6% 3 3 4 4 5% 8% 52%	2850
	11th to 20th	Night	4 3 1 3 2 2 4 3 6% 8% 63%	2850
	21st to end	Night	3 2 1 3 3 3 4 4 7% 11% 59%	3098
August	1st to 10th	Night	3 3 1 3 4 3 4 3 5% 10% 59%	2836
	11th to 20th	Night	11% 5% 2 5% 4 4 4 3 5% 8% 51%	2798
	21st to end	Night	7% 4 2 5% 3 3 4 3 5% 8% 56%	3197
September	1st to 10th	Night	8% 4 2 4 3 2 3 3 5% 7% 61%	1984
	11th to 20th	Night	8% 3 1 3 3 2 3 3 5% 8% 59%	2090
	21st to end	Night	9% 5% 1 4 3 3 4 2 4 5% 60%	2090
October	1st to 10th	Night	12% 5% 2 4 3 4 4 4 5% 6% 51%	2208
	11th to 20th	Night	12% 5% 1 4 3 3 3 2 4 6% 57%	2280
	21st to end	Night	13% 6% 2 4 3 3 3 3 4 5% 52%	2508
November	1st to 10th	Night	7% 4 1 4 3 3 3 4 5% 7% 58%	2413
	11th to 20th	Night	9% 7% 2 6% 4 3 3 2 5% 6% 52%	2500
	21st to end	Night	12% 7% 3 5% 3 3 3 3 4 6% 52%	2660
December	1st to 10th	Night	8% 7% 3 7% 5% 5% 4 3 5% 7% 46%	2660
	11th to 20th	Night	9% 9% 2 6% 4 3 4 3 5% 6% 49%	3279
	21st to end	Night	17% 14% 6% 12% 4 3 2 3 4 4 32%	4742

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	56% 7% 14% 15% 7% 1	2848
	11th to 20th	Day	49% 6% 16% 20% 9%	2850
	21st to end	Day	52% 8% 13% 17% 9%	3135
February	1st to 10th	Day	48% 7% 16% 18% 10% 1	1710
	11th to 20th	Day	42% 6% 12% 22% 14% 3	1716
	21st to end	Day	38% 6% 14% 24% 14% 3	1570
March	1st to 10th	Day	38% 5% 9% 26% 18% 3	3377
	11th to 20th	Day	35% 7% 12% 28% 17% 2	3480
	21st to end	Day	53% 11% 20% 12% 4	3814
April	1st to 10th	Day	41% 5% 13% 25% 14% 2	2137
	11th to 20th	Day	42% 8% 13% 22% 13% 3	2371
	21st to end	Day	45% 7% 11% 23% 13%	2470
May	1st to 10th	Day	42% 10% 14% 20% 12% 2	4120
	11th to 20th	Day	40% 7% 11% 23% 18% 1	4086
	21st to end	Day	38% 10% 15% 22% 14% 1	4551
June	1st to 10th	Day	29% 8% 18% 29% 14% 2	2660
	11th to 20th	Day	32% 8% 13% 30% 15% 1	2660
	21st to end	Day	31% 8% 15% 28% 14% 4	2650
July	1st to 10th	Day	37% 4 15% 29% 13% 1	4056
	11th to 20th	Day	29% 5% 13% 32% 18% 3	4051
	21st to end	Day	23% 6% 19% 29% 21% 2	4325
August	1st to 10th	Day	30% 8% 16% 27% 17% 2	4090
	11th to 20th	Day	38% 6% 15% 25% 15% 1	4080
	21st to end	Day	31% 6% 16% 25% 17% 6%	4467
September	1st to 10th	Day	31% 5% 11% 29% 18% 5%	2193
	11th to 20th	Day	30% 5% 12% 32% 19% 1	2090
	21st to end	Day	28% 5% 10% 31% 25% 1	2090
October	1st to 10th	Day	33% 6% 12% 24% 24% 2	1952
	11th to 20th	Day	30% 4 10% 27% 23% 6%	1900
	21st to end	Day	38% 6% 12% 21% 20% 4	2090
November	1st to 10th	Day	30% 4 16% 28% 20% 3	1707
	11th to 20th	Day	36% 7% 13% 24% 19% 1	1677
	21st to end	Day	39% 5% 11% 30% 14% 1	1520
December	1st to 10th	Day	38% 5% 16% 26% 14% 2	1520
	11th to 20th	Day	43% 6% 17% 27% 7%	1915
	21st to end	Day	58% 7% 10% 18% 7%	2920
January	1st to 10th	Night	52% 9% 12% 16% 11%	4108
	11th to 20th	Night	42% 7% 16% 24% 10% 1	4120
	21st to end	Night	48% 7% 16% 18% 9% 1	4532
February	1st to 10th	Night	47% 5% 14% 19% 12% 3	2470
	11th to 20th	Night	39% 6% 15% 22% 15% 3	2376
	21st to end	Night	34% 6% 11% 25% 20% 5%	1884
March	1st to 10th	Night	32% 6% 10% 27% 22% 3	3467
	11th to 20th	Night	30% 5% 9% 29% 21% 5%	3480
	21st to end	Night	47% 10% 21% 16% 5% 1	3817
April	1st to 10th	Night	36% 6% 11% 26% 17% 3	2043
	11th to 20th	Night	36% 7% 12% 26% 17% 3	1755
	21st to end	Night	40% 6% 12% 23% 18% 1	1710
May	1st to 10th	Night	39% 7% 12% 23% 17% 2	2850
	11th to 20th	Night	33% 7% 12% 25% 22% 1	2824
	21st to end	Night	38% 8% 13% 20% 18% 2	3019
June	1st to 10th	Night	25% 9% 14% 33% 16% 3	1520
	11th to 20th	Night	26% 9% 15% 27% 19% 5%	1520
	21st to end	Night	22% 8% 15% 31% 21% 3	1524
July	1st to 10th	Night	31% 5% 14% 30% 17% 3	2805
	11th to 20th	Night	19% 5% 15% 36% 22% 3	2796
	21st to end	Night	18% 7% 17% 31% 24% 2	2999
August	1st to 10th	Night	22% 5% 16% 35% 20% 2	2826
	11th to 20th	Night	33% 4 16% 28% 18% 2	2825
	21st to end	Night	27% 5% 16% 26% 17% 9%	3197
September	1st to 10th	Night	25% 4 12% 28% 23% 7%	1984
	11th to 20th	Night	23% 7% 13% 34% 20% 4	2090
	21st to end	Night	27% 4 8% 28% 28% 5%	2090
October	1st to 10th	Night	31% 7% 11% 23% 25% 3	2208
	11th to 20th	Night	30% 4 9% 24% 27% 7%	2280
	21st to end	Night	34% 5% 11% 23% 24% 2	2508
November	1st to 10th	Night	25% 6% 14% 26% 24% 5%	2413
	11th to 20th	Night	33% 4 12% 29% 19% 3	2500
	21st to end	Night	35% 4 12% 28% 20% 2	2660
December	1st to 10th	Night	37% 6% 14% 28% 14% 1	2660
	11th to 20th	Night	35% 6% 14% 35% 10%	3281
	21st to end	Night	56% 6% 10% 20% 8% 1	4742

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	18% 14% 36% 22% 8% 2	270
	11th to 20th	Day	20% 14% 34% 24% 7% 1	270
	21st to end	Day	13% 14% 43% 21% 7% 2	297
February	1st to 10th	Day	16% 17% 43% 21% 2	270
	11th to 20th	Day	16% 14% 39% 23% 7% 1	270
	21st to end	Day	15% 20% 39% 21% 4	225
March	1st to 10th	Day	17% 14% 41% 23% 4 1	270
	11th to 20th	Day	27% 8% 37% 20% 6% 1	270
	21st to end	Day	30% 17% 34% 16% 3	297
April	1st to 10th	Day	20% 16% 42% 18% 3	317
	11th to 20th	Day	20% 15% 37% 21% 7%	569
	21st to end	Day	22% 18% 29% 22% 8% 2	650
May	1st to 10th	Day	19% 13% 33% 25% 9% 1	653
	11th to 20th	Day	17% 10% 31% 28% 12% 2	675
	21st to end	Day	17% 9% 29% 29% 15% 2	734
June	1st to 10th	Day	6% 5% 23% 36% 24% 5%	680
	11th to 20th	Day	10% 6% 28% 36% 16% 4	680
	21st to end	Day	7% 7% 31% 36% 15% 3	680
July	1st to 10th	Day	9% 4 15% 33% 29% 9%	671
	11th to 20th	Day	5% 4 22% 40% 22% 7%	668
	21st to end	Day	6% 1 18% 42% 29% 4	739
August	1st to 10th	Day	6% 2 21% 43% 24% 4	676
	11th to 20th	Day	9% 2 18% 42% 25% 4	665
	21st to end	Day	9% 2 23% 35% 26% 5%	710
September	1st to 10th	Day	12% 4 27% 36% 17% 4	403
	11th to 20th	Day	7% 3 30% 36% 20% 5%	300
	21st to end	Day	14% 8% 31% 28% 16% 4	300
October	1st to 10th	Day	20% 6% 26% 29% 14% 6%	300
	11th to 20th	Day	11% 16% 40% 22% 10% 1	300
	21st to end	Day	18% 14% 38% 20% 8% 2	330
November	1st to 10th	Day	14% 13% 36% 26% 9% 2	276
	11th to 20th	Day	14% 15% 41% 22% 8%	270
	21st to end	Day	21% 11% 33% 26% 8% 1	270
December	1st to 10th	Day	9% 12% 40% 30% 7% 2	270
	11th to 20th	Day	15% 14% 32% 31% 8%	270
	21st to end	Day	20% 14% 42% 20% 4	297
January	1st to 10th	Night	12% 12% 36% 34% 6%	950
	11th to 20th	Night	14% 13% 36% 30% 7%	950
	21st to end	Night	17% 8% 38% 32% 5%	1045
February	1st to 10th	Night	16% 10% 40% 29% 4	950
	11th to 20th	Night	12% 10% 44% 30% 5%	901
	21st to end	Night	14% 13% 43% 25% 5%	628
March	1st to 10th	Night	13% 13% 39% 27% 7%	607
	11th to 20th	Night	18% 9% 38% 28% 7%	570
	21st to end	Night	22% 11% 39% 22% 6%	627
April	1st to 10th	Night	16% 16% 40% 24% 5%	570
	11th to 20th	Night	15% 13% 39% 28% 3 1	563
	21st to end	Night	18% 11% 36% 27% 7%	570
May	1st to 10th	Night	17% 10% 35% 29% 9%	570
	11th to 20th	Night	15% 8% 32% 35% 9% 1	561
	21st to end	Night	17% 8% 30% 31% 14% 1	617
June	1st to 10th	Night	7% 3 25% 47% 17%	570
	11th to 20th	Night	8% 4 32% 43% 13% 1	570
	21st to end	Night	5% 4 32% 46% 14%	570
July	1st to 10th	Night	8% 2 17% 43% 30% 1	555
	11th to 20th	Night	3 2 17% 51% 26% 1	552
	21st to end	Night	3 14% 55% 25% 1	624
August	1st to 10th	Night	4 2 20% 49% 23% 2	567
	11th to 20th	Night	8% 2 16% 49% 24% 1	564
	21st to end	Night	8% 2 22% 41% 25% 3	627
September	1st to 10th	Night	9% 3 23% 43% 20% 2	570
	11th to 20th	Night	10% 1 30% 41% 17% 1	570
	21st to end	Night	11% 5% 31% 35% 16% 1	570
October	1st to 10th	Night	14% 8% 30% 35% 12% 2	688
	11th to 20th	Night	15% 10% 36% 32% 8%	760
	21st to end	Night	18% 10% 31% 32% 9%	836
November	1st to 10th	Night	9% 10% 33% 37% 10% 1	917
	11th to 20th	Night	13% 11% 39% 31% 6%	950
	21st to end	Night	15% 11% 35% 30% 8% 1	950
December	1st to 10th	Night	13% 11% 39% 32% 6%	950
	11th to 20th	Night	16% 9% 34% 34% 6%	950
	21st to end	Night	20% 12% 34% 30% 4	1045

Page generated at 2024-10-31 02:39:26. Version ac07

Copyright © 2024 Attilla Danko.