Baxter State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Baxter State Park clear sky chart from 2005-11-06 to 2025-02-06.

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% 13% 5% 11% 6% 5% 5% 4 5% 6% 27%	107908
	Night	14% 13% 5% 12% 7% 6% 5% 3 5% 5% 26%	110410
Transparency	Day	52% 9% 11% 17% 9% 1	111443
	Night	50% 11% 12% 17% 9% 1	115040
Seeing	Day	25% 23% 29% 16% 6% 1	15992
	Night	22% 20% 29% 21% 7%	24371

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	8% 18% 7% 18% 8% 7% 6% 3 3 4 18%	3438
	11th to 20th	Day	7% 13% 5% 22% 13% 9% 4 3 3 3 18%	3570
	21st to end	Day	6% 9% 5% 18% 9% 9% 7% 5% 5% 5% 21%	3960
February	1st to 10th	Day	12% 14% 5% 14% 10% 6% 5% 4 5% 5% 19%	1714
	11th to 20th	Day	10% 16% 8% 15% 8% 7% 5% 3 4 3 20%	1743
	21st to end	Day	9% 16% 5% 13% 7% 6% 5% 4 4 4 26%	1570
March	1st to 10th	Day	16% 18% 5% 11% 5% 5% 4 3 4 4 25%	3116
	11th to 20th	Day	12% 25% 9% 13% 6% 4 3 2 3 3 18%	3476
	21st to end	Day	18% 16% 6% 11% 6% 4 3 3 3 5% 26%	3832
April	1st to 10th	Day	17% 18% 5% 11% 6% 4 4 4 4 4 23%	2280
	11th to 20th	Day	17% 17% 4 8% 5% 3 3 4 4 4 31%	2430
	21st to end	Day	20% 15% 5% 8% 4 3 4 3 4 5% 29%	2470
May	1st to 10th	Day	17% 13% 4 8% 6% 5% 5% 4 5% 5% 28%	4106
	11th to 20th	Day	20% 10% 4 8% 5% 5% 6% 4 6% 6% 25%	4194
	21st to end	Day	14% 9% 3 9% 7% 6% 6% 4 7% 7% 27%	5145
June	1st to 10th	Day	23% 13% 3 8% 5% 4 5% 3 6% 6% 24%	2850
	11th to 20th	Day	19% 9% 3 6% 5% 5% 5% 4 6% 7% 31%	2850
	21st to end	Day	23% 11% 3 8% 6% 5% 5% 4 6% 6% 22%	2850
July	1st to 10th	Day	13% 8% 3 8% 7% 7% 6% 5% 7% 7% 27%	4760
	11th to 20th	Day	14% 9% 3 8% 5% 5% 6% 5% 6% 8% 31%	4446
	21st to end	Day	13% 8% 3 8% 6% 5% 5% 4 6% 8% 34%	4814
August	1st to 10th	Day	17% 9% 3 8% 6% 6% 6% 5% 6% 7% 27%	4147
	11th to 20th	Day	15% 9% 4 9% 7% 6% 7% 6% 7% 7% 23%	4045
	21st to end	Day	15% 10% 3 7% 4 5% 5% 4 6% 7% 34%	4532
September	1st to 10th	Day	14% 8% 3 6% 5% 4 4 4 5% 7% 40%	2214
	11th to 20th	Day	15% 8% 3 6% 5% 4 3 3 4 5% 45%	2090
	21st to end	Day	16% 9% 3 7% 4 5% 4 4 5% 6% 37%	2090
October	1st to 10th	Day	16% 11% 4 8% 5% 4 5% 3 4 7% 32%	2033
	11th to 20th	Day	19% 14% 4 9% 4 4 4 3 4 6% 28%	1848
	21st to end	Day	18% 15% 5% 11% 6% 4 3 3 4 6% 25%	1881
November	1st to 10th	Day	17% 17% 4 9% 5% 3 4 3 3 6% 29%	1761
	11th to 20th	Day	13% 16% 6% 12% 6% 4 4 3 4 6% 25%	1691
	21st to end	Day	17% 15% 4 13% 7% 5% 5% 4 4 6% 20%	1588
December	1st to 10th	Day	12% 18% 6% 18% 8% 7% 5% 3 4 4 15%	2280
	11th to 20th	Day	13% 17% 9% 11% 5% 4 3 3 3 4 28%	2618
	21st to end	Day	12% 17% 7% 13% 7% 4 5% 3 3 4 24%	3476
January	1st to 10th	Night	9% 15% 8% 18% 12% 9% 6% 3 3 4 13%	6509
	11th to 20th	Night	8% 15% 7% 19% 14% 8% 4 3 4 3 13%	6315
	21st to end	Night	7% 9% 4 16% 9% 8% 7% 4 6% 5% 24%	6996
February	1st to 10th	Night	10% 15% 5% 13% 8% 8% 7% 4 5% 5% 21%	2576
	11th to 20th	Night	10% 16% 8% 15% 8% 7% 5% 4 5% 5% 19%	2322
	21st to end	Night	12% 14% 4 10% 8% 7% 4 3 5% 5% 28%	1884
March	1st to 10th	Night	17% 17% 6% 11% 6% 4 6% 3 3 4 24%	3724
	11th to 20th	Night	11% 22% 8% 13% 6% 5% 4 4 4 4 18%	3482
	21st to end	Night	20% 16% 5% 10% 6% 4 4 3 4 6% 22%	3799
April	1st to 10th	Night	18% 19% 5% 9% 4 3 4 3 4 5% 27%	1900
	11th to 20th	Night	17% 13% 3 8% 4 4 4 3 6% 6% 33%	1698
	21st to end	Night	20% 14% 4 10% 6% 4 3 3 4 5% 27%	1710
May	1st to 10th	Night	20% 11% 3 7% 4 4 4 4 5% 8% 30%	2834
	11th to 20th	Night	17% 10% 3 10% 6% 6% 6% 4 5% 6% 27%	2727
	21st to end	Night	16% 7% 2 6% 5% 5% 5% 4 6% 9% 36%	2440
June	1st to 10th	Night	23% 11% 3 8% 4 4 4 3 5% 7% 28%	1330
	11th to 20th	Night	16% 9% 4 7% 4 5% 5% 4 5% 7% 34%	1330
	21st to end	Night	18% 12% 5% 8% 4 4 5% 4 5% 6% 30%	1330
July	1st to 10th	Night	11% 9% 3 10% 6% 5% 5% 4 5% 8% 32%	2210
	11th to 20th	Night	15% 8% 4 9% 6% 5% 5% 3 6% 7% 31%	2510
	21st to end	Night	11% 8% 4 8% 6% 5% 5% 4 6% 7% 37%	2739
August	1st to 10th	Night	17% 10% 3 9% 6% 5% 5% 4 6% 7% 28%	2750
	11th to 20th	Night	12% 8% 4 10% 6% 7% 6% 5% 8% 7% 28%	2782
	21st to end	Night	12% 9% 3 7% 4 4 4 3 4 6% 45%	3124
September	1st to 10th	Night	13% 7% 2 6% 4 4 4 4 5% 7% 43%	1962
	11th to 20th	Night	14% 8% 3 6% 3 3 3 3 5% 6% 45%	2090
	21st to end	Night	13% 10% 3 9% 5% 3 3 3 5% 6% 39%	2090
October	1st to 10th	Night	16% 8% 3 7% 5% 3 4 4 5% 7% 38%	2147
	11th to 20th	Night	16% 14% 3 9% 5% 4 5% 4 4 5% 32%	2327
	21st to end	Night	18% 15% 4 10% 4 5% 5% 3 4 6% 27%	2717
November	1st to 10th	Night	18% 12% 4 10% 5% 5% 5% 4 4 5% 28%	2537
	11th to 20th	Night	14% 15% 5% 12% 6% 4 4 3 4 5% 29%	2706
	21st to end	Night	14% 15% 6% 13% 8% 6% 4 4 4 5% 20%	2810
December	1st to 10th	Night	12% 15% 6% 21% 11% 9% 5% 3 3 3 12%	4910
	11th to 20th	Night	14% 17% 6% 14% 8% 6% 5% 3 4 4 20%	5591
	21st to end	Night	14% 17% 6% 12% 8% 5% 4 2 3 3 25%	7502

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	59% 11% 12% 13% 6%	3439
	11th to 20th	Day	56% 15% 8% 14% 7% 1	3600
	21st to end	Day	54% 11% 7% 11% 16% 1	3960
February	1st to 10th	Day	59% 9% 8% 13% 8% 2	1714
	11th to 20th	Day	60% 9% 9% 12% 9% 1	1751
	21st to end	Day	55% 8% 8% 16% 9% 3	1570
March	1st to 10th	Day	60% 6% 7% 11% 12% 3	3119
	11th to 20th	Day	66% 8% 9% 9% 7% 1	3476
	21st to end	Day	60% 5% 6% 15% 12% 3	3832
April	1st to 10th	Day	61% 6% 9% 13% 9% 2	2280
	11th to 20th	Day	54% 6% 8% 17% 13% 1	2430
	21st to end	Day	57% 4 8% 17% 11% 3	2470
May	1st to 10th	Day	53% 8% 10% 19% 9% 1	4120
	11th to 20th	Day	52% 9% 15% 16% 6% 1	4198
	21st to end	Day	50% 11% 11% 17% 12%	5145
June	1st to 10th	Day	57% 7% 12% 16% 8%	2850
	11th to 20th	Day	49% 8% 12% 19% 10% 2	2850
	21st to end	Day	58% 8% 11% 14% 8%	2850
July	1st to 10th	Day	46% 12% 15% 19% 8%	4685
	11th to 20th	Day	45% 10% 14% 26% 5%	4370
	21st to end	Day	44% 11% 12% 25% 8%	4661
August	1st to 10th	Day	50% 10% 14% 21% 5%	4133
	11th to 20th	Day	49% 12% 16% 18% 5%	4084
	21st to end	Day	42% 11% 15% 19% 13%	4532
September	1st to 10th	Day	39% 9% 14% 23% 13% 1	2214
	11th to 20th	Day	40% 6% 12% 27% 15% 1	2090
	21st to end	Day	44% 8% 10% 25% 13%	2090
October	1st to 10th	Day	53% 9% 12% 19% 7%	3384
	11th to 20th	Day	43% 15% 11% 21% 10%	3051
	21st to end	Day	42% 9% 18% 17% 14%	3081
November	1st to 10th	Day	54% 7% 12% 17% 9% 1	1761
	11th to 20th	Day	54% 9% 11% 15% 9% 2	1691
	21st to end	Day	57% 11% 15% 13% 4	1588
December	1st to 10th	Day	59% 15% 9% 10% 7%	2280
	11th to 20th	Day	51% 9% 11% 11% 14% 3	2618
	21st to end	Day	57% 9% 8% 13% 9% 5%	3476
January	1st to 10th	Night	59% 16% 12% 10% 3	6509
	11th to 20th	Night	61% 14% 12% 10% 3 1	6360
	21st to end	Night	48% 12% 9% 14% 15% 3	6996
February	1st to 10th	Night	56% 10% 10% 13% 8% 2	2576
	11th to 20th	Night	60% 10% 9% 12% 8% 1	2325
	21st to end	Night	51% 8% 10% 17% 11% 2	1884
March	1st to 10th	Night	59% 9% 7% 16% 7% 2	3734
	11th to 20th	Night	61% 10% 11% 10% 7% 1	3483
	21st to end	Night	59% 5% 7% 18% 9% 2	3799
April	1st to 10th	Night	56% 6% 7% 15% 13% 3	1900
	11th to 20th	Night	48% 7% 10% 20% 14% 2	1698
	21st to end	Night	57% 6% 7% 16% 11% 3	1710
May	1st to 10th	Night	47% 9% 15% 19% 8% 1	2840
	11th to 20th	Night	52% 10% 13% 18% 6%	2728
	21st to end	Night	40% 11% 16% 21% 12%	2441
June	1st to 10th	Night	55% 6% 12% 19% 8%	1330
	11th to 20th	Night	46% 8% 13% 20% 11% 2	1330
	21st to end	Night	52% 8% 14% 16% 8%	1330
July	1st to 10th	Night	42% 12% 16% 21% 9%	2175
	11th to 20th	Night	43% 10% 15% 26% 5%	2463
	21st to end	Night	38% 13% 17% 24% 8%	2651
August	1st to 10th	Night	50% 9% 16% 22% 3	2740
	11th to 20th	Night	43% 15% 17% 19% 6%	2809
	21st to end	Night	36% 10% 16% 22% 13% 3	3124
September	1st to 10th	Night	35% 8% 16% 29% 11% 1	1962
	11th to 20th	Night	38% 6% 13% 29% 13%	2090
	21st to end	Night	43% 8% 12% 23% 14% 1	2090
October	1st to 10th	Night	43% 11% 12% 23% 11%	3576
	11th to 20th	Night	38% 16% 11% 24% 10%	3863
	21st to end	Night	41% 11% 18% 19% 10% 1	4467
November	1st to 10th	Night	50% 11% 13% 19% 7% 1	2537
	11th to 20th	Night	50% 9% 13% 16% 10% 2	2706
	21st to end	Night	54% 11% 18% 12% 5%	2810
December	1st to 10th	Night	56% 20% 10% 11% 3	4910
	11th to 20th	Night	54% 12% 8% 12% 13%	5592
	21st to end	Night	55% 10% 9% 13% 11% 2	7502

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	28% 33% 29% 11%	200
	11th to 20th	Day	32% 31% 28% 8% 2 1	200
	21st to end	Day	24% 30% 35% 9% 3	220
February	1st to 10th	Day	26% 28% 30% 12% 3 1	344
	11th to 20th	Day	28% 32% 28% 9% 2	404
	21st to end	Day	24% 32% 30% 12% 2	382
March	1st to 10th	Day	28% 29% 30% 10% 3	460
	11th to 20th	Day	26% 26% 30% 13% 3 1	460
	21st to end	Day	30% 26% 23% 14% 5% 1	506
April	1st to 10th	Day	34% 26% 22% 12% 5% 1	460
	11th to 20th	Day	33% 27% 24% 12% 4 2	452
	21st to end	Day	30% 25% 31% 10% 3 1	460
May	1st to 10th	Day	31% 21% 31% 13% 3 1	463
	11th to 20th	Day	26% 25% 29% 15% 4 1	487
	21st to end	Day	22% 23% 32% 17% 5%	707
June	1st to 10th	Day	28% 21% 29% 14% 7% 1	680
	11th to 20th	Day	22% 18% 30% 20% 9% 1	680
	21st to end	Day	25% 16% 32% 18% 8% 1	680
July	1st to 10th	Day	17% 18% 33% 21% 10% 1	670
	11th to 20th	Day	17% 17% 39% 18% 9% 1	489
	21st to end	Day	18% 13% 36% 25% 6% 1	532
August	1st to 10th	Day	18% 15% 34% 25% 7% 1	486
	11th to 20th	Day	18% 15% 29% 27% 9% 2	479
	21st to end	Day	19% 18% 30% 21% 11% 2	539
September	1st to 10th	Day	16% 19% 31% 22% 9% 3	490
	11th to 20th	Day	19% 16% 27% 23% 9% 5%	490
	21st to end	Day	19% 21% 28% 18% 9% 5%	490
October	1st to 10th	Day	18% 20% 30% 19% 10% 3	460
	11th to 20th	Day	27% 25% 26% 13% 7% 2	390
	21st to end	Day	28% 28% 26% 15% 3	429
November	1st to 10th	Day	30% 23% 26% 17% 4	395
	11th to 20th	Day	27% 27% 28% 11% 7% 1	400
	21st to end	Day	33% 25% 26% 13% 3	388
December	1st to 10th	Day	28% 28% 28% 13% 4	200
	11th to 20th	Day	38% 28% 24% 7% 5%	200
	21st to end	Day	29% 34% 23% 10% 4	220
January	1st to 10th	Night	21% 28% 33% 16% 2	835
	11th to 20th	Night	24% 27% 29% 17% 4	800
	21st to end	Night	16% 29% 36% 16% 3	880
February	1st to 10th	Night	20% 29% 31% 17% 3	781
	11th to 20th	Night	23% 29% 32% 14% 2	743
	21st to end	Night	21% 26% 34% 16% 2	628
March	1st to 10th	Night	24% 23% 34% 17% 1	760
	11th to 20th	Night	22% 24% 29% 18% 7%	760
	21st to end	Night	22% 23% 29% 20% 6%	836
April	1st to 10th	Night	29% 23% 28% 15% 5%	760
	11th to 20th	Night	23% 23% 27% 20% 6%	574
	21st to end	Night	31% 19% 24% 19% 6%	570
May	1st to 10th	Night	26% 16% 27% 25% 6% 1	570
	11th to 20th	Night	24% 16% 29% 23% 8%	515
	21st to end	Night	21% 11% 34% 26% 8%	411
June	1st to 10th	Night	26% 11% 29% 24% 9%	380
	11th to 20th	Night	19% 13% 23% 33% 12%	380
	21st to end	Night	24% 11% 26% 30% 9%	380
July	1st to 10th	Night	16% 11% 29% 33% 10% 1	370
	11th to 20th	Night	14% 8% 29% 36% 13% 1	368
	21st to end	Night	18% 8% 28% 33% 13%	416
August	1st to 10th	Night	18% 8% 25% 34% 15%	518
	11th to 20th	Night	15% 9% 29% 31% 16% 1	562
	21st to end	Night	15% 9% 26% 33% 15% 1	627
September	1st to 10th	Night	14% 13% 29% 29% 14% 1	747
	11th to 20th	Night	16% 15% 23% 31% 14% 2	760
	21st to end	Night	19% 14% 28% 26% 13% 1	760
October	1st to 10th	Night	20% 14% 27% 26% 11% 1	760
	11th to 20th	Night	23% 18% 29% 21% 8% 1	760
	21st to end	Night	26% 24% 27% 18% 4	836
November	1st to 10th	Night	25% 20% 29% 19% 6%	780
	11th to 20th	Night	22% 27% 26% 17% 7% 1	854
	21st to end	Night	26% 26% 26% 17% 4 1	900
December	1st to 10th	Night	25% 25% 32% 13% 3 1	900
	11th to 20th	Night	28% 25% 27% 16% 3	900
	21st to end	Night	27% 27% 28% 15% 3	990

Page generated at 2025-02-03 03:05:52. Version ac07

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