Haliburton County
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Haliburton County clear sky chart from 2005-11-06 to 2025-02-25.

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% 12% 4 9% 5% 5% 4 3 5% 6% 30%	109135
	Night	16% 14% 5% 10% 5% 4 4 3 5% 6% 28%	109502
Transparency	Day	53% 6% 11% 19% 9% 1	112750
	Night	56% 6% 10% 18% 9% 1	114050
Seeing	Day	24% 17% 30% 19% 8% 2	14905
	Night	23% 14% 30% 22% 9% 1	24074

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	12% 18% 6% 15% 5% 5% 4 3 5% 4 22%	3597
	11th to 20th	Day	10% 21% 10% 19% 8% 6% 4 3 4 3 13%	3634
	21st to end	Day	12% 20% 10% 15% 7% 6% 4 2 3 3 17%	4466
February	1st to 10th	Day	12% 19% 7% 17% 9% 6% 3 3 3 3 19%	1800
	11th to 20th	Day	12% 16% 7% 15% 6% 5% 4 3 4 5% 23%	1753
	21st to end	Day	17% 18% 6% 12% 7% 4 4 4 4 4 21%	1493
March	1st to 10th	Day	18% 17% 4 9% 5% 3 3 3 5% 6% 26%	3384
	11th to 20th	Day	10% 19% 7% 11% 6% 4 4 3 5% 5% 24%	3480
	21st to end	Day	13% 11% 4 8% 5% 4 3 3 4 5% 39%	3839
April	1st to 10th	Day	20% 15% 4 6% 5% 4 4 3 4 6% 27%	2280
	11th to 20th	Day	23% 12% 3 6% 3 5% 3 2 4 5% 34%	2299
	21st to end	Day	22% 13% 4 6% 4 4 3 2 3 5% 32%	2470
May	1st to 10th	Day	19% 8% 3 8% 6% 5% 4 4 5% 7% 32%	4263
	11th to 20th	Day	15% 9% 3 7% 5% 4 4 4 5% 9% 34%	4398
	21st to end	Day	17% 7% 2 6% 4 4 5% 4 5% 7% 40%	4837
June	1st to 10th	Day	20% 9% 3 7% 5% 4 4 4 5% 7% 30%	2660
	11th to 20th	Day	16% 7% 3 6% 5% 5% 5% 4 6% 8% 35%	2668
	21st to end	Day	17% 8% 3 7% 5% 5% 5% 4 7% 7% 33%	2850
July	1st to 10th	Day	14% 6% 2 6% 6% 5% 5% 5% 7% 10% 34%	4546
	11th to 20th	Day	13% 6% 2 6% 5% 5% 4 4 6% 8% 41%	4440
	21st to end	Day	9% 7% 2 6% 5% 4 4 4 7% 8% 44%	4735
August	1st to 10th	Day	16% 9% 3 8% 5% 5% 5% 4 6% 8% 32%	4104
	11th to 20th	Day	17% 8% 3 7% 5% 5% 6% 4 7% 8% 32%	4044
	21st to end	Day	10% 5% 2 6% 4 6% 5% 5% 7% 10% 40%	4318
September	1st to 10th	Day	17% 8% 2 5% 4 5% 4 4 6% 7% 38%	2280
	11th to 20th	Day	13% 7% 2 6% 4 4 4 4 5% 7% 44%	2237
	21st to end	Day	19% 8% 2 7% 5% 4 5% 4 5% 6% 35%	2009
October	1st to 10th	Day	21% 9% 3 8% 5% 4 4 3 5% 7% 32%	1900
	11th to 20th	Day	26% 12% 3 9% 5% 5% 4 3 4 5% 24%	1900
	21st to end	Day	29% 14% 4 9% 5% 4 4 3 4 5% 20%	2077
November	1st to 10th	Day	18% 14% 3 8% 5% 4 4 3 5% 6% 29%	1628
	11th to 20th	Day	17% 18% 6% 9% 5% 4 5% 4 5% 6% 22%	1600
	21st to end	Day	20% 24% 7% 10% 6% 5% 3 3 4 4 14%	1600
December	1st to 10th	Day	16% 26% 9% 11% 5% 4 4 3 4 4 11%	2600
	11th to 20th	Day	18% 22% 7% 17% 5% 3 2 2 2 3 18%	2986
	21st to end	Day	22% 21% 7% 13% 5% 3 2 2 3 4 18%	3960
January	1st to 10th	Night	14% 18% 8% 15% 6% 5% 4 3 5% 4 18%	6349
	11th to 20th	Night	11% 17% 8% 22% 10% 6% 4 3 3 4 11%	6249
	21st to end	Night	12% 19% 9% 16% 6% 7% 5% 3 4 4 16%	6490
February	1st to 10th	Night	12% 19% 6% 13% 8% 6% 5% 3 5% 5% 18%	2600
	11th to 20th	Night	12% 16% 7% 13% 6% 6% 4 3 4 4 25%	2533
	21st to end	Night	15% 18% 5% 11% 7% 5% 5% 3 6% 5% 22%	2055
March	1st to 10th	Night	17% 14% 6% 10% 5% 4 4 3 4 5% 29%	3452
	11th to 20th	Night	12% 19% 7% 9% 5% 4 4 3 5% 5% 26%	3479
	21st to end	Night	14% 10% 4 9% 6% 4 4 4 6% 7% 34%	3791
April	1st to 10th	Night	21% 17% 4 7% 4 4 3 2 5% 5% 30%	1900
	11th to 20th	Night	18% 12% 4 7% 4 3 4 2 4 6% 35%	1848
	21st to end	Night	20% 11% 3 8% 6% 4 4 3 5% 5% 31%	1710
May	1st to 10th	Night	20% 7% 2 7% 5% 4 4 4 5% 7% 35%	2677
	11th to 20th	Night	15% 8% 3 6% 5% 4 4 4 6% 8% 37%	2495
	21st to end	Night	13% 7% 3 5% 4 4 4 3 5% 8% 43%	2738
June	1st to 10th	Night	16% 10% 3 7% 5% 4 4 4 6% 8% 34%	1520
	11th to 20th	Night	12% 8% 2 4 4 4 4 4 6% 7% 43%	1500
	21st to end	Night	15% 10% 3 7% 4 4 4 4 5% 7% 37%	1330
July	1st to 10th	Night	9% 7% 2 8% 5% 6% 5% 4 6% 7% 40%	2396
	11th to 20th	Night	16% 7% 2 5% 4 4 4 3 5% 7% 44%	2520
	21st to end	Night	11% 6% 2 5% 3 4 3 4 5% 8% 48%	2814
August	1st to 10th	Night	12% 5% 2 6% 4 3 5% 4 6% 8% 46%	2825
	11th to 20th	Night	15% 9% 3 7% 4 3 4 3 5% 6% 41%	2785
	21st to end	Night	13% 5% 2 5% 3 4 4 3 6% 8% 48%	3305
September	1st to 10th	Night	13% 6% 2 6% 4 4 4 4 5% 7% 45%	1900
	11th to 20th	Night	14% 6% 2 5% 4 3 4 3 4 6% 49%	1939
	21st to end	Night	19% 8% 3 6% 4 4 4 3 4 6% 40%	2171
October	1st to 10th	Night	19% 8% 3 6% 4 4 4 3 5% 6% 37%	2280
	11th to 20th	Night	24% 12% 3 8% 4 4 5% 3 4 5% 28%	2280
	21st to end	Night	24% 16% 3 9% 5% 4 3 3 5% 5% 24%	2519
November	1st to 10th	Night	21% 12% 3 8% 4 4 4 2 5% 6% 31%	2668
	11th to 20th	Night	18% 15% 5% 8% 6% 4 4 3 5% 7% 26%	2800
	21st to end	Night	21% 19% 5% 10% 5% 5% 4 3 4 5% 18%	2800
December	1st to 10th	Night	19% 25% 7% 12% 6% 4 3 3 4 4 12%	4580
	11th to 20th	Night	17% 23% 7% 16% 5% 4 4 3 3 4 14%	5208
	21st to end	Night	23% 21% 7% 13% 6% 3 3 2 3 4 15%	6996

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	62% 5% 8% 16% 8%	3598
	11th to 20th	Day	77% 4 5% 8% 6% 1	3664
	21st to end	Day	72% 4 6% 9% 8% 1	4466
February	1st to 10th	Day	70% 5% 7% 12% 5% 1	1800
	11th to 20th	Day	63% 6% 9% 11% 9% 2	1762
	21st to end	Day	66% 5% 8% 12% 9% 1	1493
March	1st to 10th	Day	59% 6% 13% 10% 11% 1	3387
	11th to 20th	Day	60% 6% 11% 15% 7% 1	3480
	21st to end	Day	45% 5% 9% 23% 15% 3	3839
April	1st to 10th	Day	57% 5% 8% 17% 10% 2	2280
	11th to 20th	Day	54% 4 7% 21% 13% 1	2299
	21st to end	Day	55% 5% 7% 18% 11% 3	2470
May	1st to 10th	Day	49% 7% 9% 22% 11% 2	4275
	11th to 20th	Day	46% 8% 11% 25% 9% 1	4402
	21st to end	Day	42% 8% 12% 19% 15% 3	4837
June	1st to 10th	Day	51% 7% 10% 19% 12% 1	2660
	11th to 20th	Day	45% 7% 11% 23% 13% 2	2668
	21st to end	Day	48% 8% 12% 20% 10% 1	2850
July	1st to 10th	Day	42% 8% 15% 24% 11% 1	4476
	11th to 20th	Day	38% 7% 16% 30% 9%	4365
	21st to end	Day	36% 7% 12% 32% 13%	4584
August	1st to 10th	Day	48% 8% 13% 21% 9% 1	4091
	11th to 20th	Day	46% 8% 14% 25% 7%	4083
	21st to end	Day	36% 8% 13% 33% 9%	4318
September	1st to 10th	Day	44% 6% 12% 25% 11% 1	2280
	11th to 20th	Day	38% 7% 13% 28% 13% 1	2237
	21st to end	Day	49% 7% 11% 23% 11%	2009
October	1st to 10th	Day	47% 7% 13% 24% 9% 1	3160
	11th to 20th	Day	53% 6% 11% 19% 10% 1	3140
	21st to end	Day	61% 6% 11% 17% 5%	3403
November	1st to 10th	Day	54% 7% 13% 18% 7% 1	1628
	11th to 20th	Day	61% 8% 11% 13% 7% 1	1600
	21st to end	Day	73% 5% 9% 8% 4 1	1600
December	1st to 10th	Day	75% 5% 10% 7% 2	2600
	11th to 20th	Day	72% 5% 5% 12% 5% 1	2986
	21st to end	Day	71% 5% 5% 12% 7%	3960
January	1st to 10th	Night	68% 5% 8% 13% 6%	6349
	11th to 20th	Night	75% 7% 6% 6% 5% 1	6294
	21st to end	Night	70% 6% 6% 8% 9% 1	6490
February	1st to 10th	Night	66% 6% 10% 12% 5% 1	2600
	11th to 20th	Night	63% 4 8% 16% 8% 1	2535
	21st to end	Night	63% 5% 9% 16% 7% 1	2055
March	1st to 10th	Night	57% 5% 10% 16% 10% 1	3462
	11th to 20th	Night	58% 6% 13% 15% 6% 1	3480
	21st to end	Night	45% 6% 11% 22% 13% 2	3791
April	1st to 10th	Night	58% 5% 7% 18% 11% 2	1900
	11th to 20th	Night	50% 5% 7% 22% 14% 1	1848
	21st to end	Night	53% 6% 9% 15% 15% 2	1710
May	1st to 10th	Night	45% 9% 11% 20% 13% 1	2684
	11th to 20th	Night	42% 10% 13% 23% 11% 1	2496
	21st to end	Night	37% 9% 11% 24% 16% 2	2739
June	1st to 10th	Night	46% 7% 12% 20% 14% 1	1520
	11th to 20th	Night	38% 6% 12% 26% 17% 1	1500
	21st to end	Night	45% 7% 15% 21% 11% 1	1330
July	1st to 10th	Night	39% 8% 16% 22% 16% 1	2356
	11th to 20th	Night	39% 6% 12% 31% 12%	2472
	21st to end	Night	34% 7% 13% 32% 14% 1	2724
August	1st to 10th	Night	35% 6% 16% 25% 16% 1	2814
	11th to 20th	Night	43% 6% 18% 22% 10% 1	2812
	21st to end	Night	34% 6% 13% 34% 12% 2	3305
September	1st to 10th	Night	37% 8% 14% 27% 13% 1	1900
	11th to 20th	Night	35% 7% 13% 31% 13% 1	1939
	21st to end	Night	46% 6% 11% 27% 11%	2171
October	1st to 10th	Night	39% 6% 11% 27% 17%	3800
	11th to 20th	Night	50% 6% 15% 20% 9%	3779
	21st to end	Night	56% 6% 14% 18% 6%	4143
November	1st to 10th	Night	54% 5% 12% 21% 8%	2668
	11th to 20th	Night	57% 7% 13% 15% 7% 1	2800
	21st to end	Night	67% 6% 10% 12% 4	2800
December	1st to 10th	Night	75% 5% 10% 8% 2	4580
	11th to 20th	Night	73% 5% 7% 9% 5%	5208
	21st to end	Night	74% 4 5% 9% 7%	6996

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	21% 27% 33% 15% 4 1	200
	11th to 20th	Day	25% 20% 38% 14% 3	213
	21st to end	Day	24% 21% 38% 13% 3	330
February	1st to 10th	Day	29% 31% 29% 9% 3	300
	11th to 20th	Day	29% 30% 34% 7%	300
	21st to end	Day	36% 23% 33% 8%	281
March	1st to 10th	Day	25% 20% 36% 15% 3	460
	11th to 20th	Day	25% 22% 33% 15% 3 1	460
	21st to end	Day	31% 20% 29% 14% 5%	506
April	1st to 10th	Day	29% 20% 32% 13% 6%	460
	11th to 20th	Day	37% 21% 20% 14% 6% 3	452
	21st to end	Day	32% 17% 33% 12% 7% 1	460
May	1st to 10th	Day	27% 18% 27% 18% 6% 3	463
	11th to 20th	Day	21% 16% 32% 19% 10% 2	487
	21st to end	Day	21% 17% 31% 19% 9% 3	529
June	1st to 10th	Day	24% 16% 32% 21% 6% 1	490
	11th to 20th	Day	18% 14% 33% 22% 10% 3	498
	21st to end	Day	21% 14% 34% 21% 8% 2	680
July	1st to 10th	Day	14% 9% 35% 29% 10% 3	552
	11th to 20th	Day	16% 11% 29% 28% 11% 4	484
	21st to end	Day	15% 11% 30% 29% 10% 3	532
August	1st to 10th	Day	16% 7% 31% 28% 13% 5%	486
	11th to 20th	Day	16% 8% 25% 32% 14% 6%	479
	21st to end	Day	18% 9% 33% 22% 13% 6%	539
September	1st to 10th	Day	18% 12% 29% 22% 13% 5%	490
	11th to 20th	Day	14% 10% 23% 22% 21% 10%	490
	21st to end	Day	23% 12% 27% 23% 12% 4	490
October	1st to 10th	Day	26% 17% 25% 16% 12% 4	490
	11th to 20th	Day	28% 23% 28% 14% 5% 1	490
	21st to end	Day	35% 19% 28% 14% 3	532
November	1st to 10th	Day	33% 16% 32% 15% 4	262
	11th to 20th	Day	30% 25% 31% 13% 2 2	200
	21st to end	Day	33% 23% 36% 8% 1 1	200
December	1st to 10th	Day	31% 21% 32% 15% 2	200
	11th to 20th	Day	36% 28% 22% 12% 2 1	200
	21st to end	Day	34% 22% 29% 10% 4 1	220
January	1st to 10th	Night	27% 20% 35% 15% 4	800
	11th to 20th	Night	29% 17% 32% 17% 4 1	800
	21st to end	Night	21% 14% 38% 20% 6% 1	880
February	1st to 10th	Night	23% 22% 33% 20% 2	800
	11th to 20th	Night	22% 21% 37% 16% 4	783
	21st to end	Night	26% 22% 31% 18% 4	647
March	1st to 10th	Night	23% 20% 35% 18% 3	760
	11th to 20th	Night	23% 18% 35% 18% 4 1	760
	21st to end	Night	21% 15% 34% 21% 8%	836
April	1st to 10th	Night	29% 17% 31% 18% 4	760
	11th to 20th	Night	26% 15% 31% 17% 9% 1	724
	21st to end	Night	25% 11% 31% 22% 11%	570
May	1st to 10th	Night	23% 8% 28% 27% 13% 1	479
	11th to 20th	Night	19% 9% 33% 30% 9%	374
	21st to end	Night	12% 9% 34% 32% 12%	411
June	1st to 10th	Night	17% 9% 35% 30% 9% 1	380
	11th to 20th	Night	16% 10% 27% 36% 11% 1	380
	21st to end	Night	21% 8% 23% 35% 13%	380
July	1st to 10th	Night	10% 5% 29% 39% 17%	370
	11th to 20th	Night	13% 5% 29% 33% 19% 1	368
	21st to end	Night	10% 5% 27% 38% 20%	455
August	1st to 10th	Night	14% 3 21% 35% 25% 2	567
	11th to 20th	Night	13% 5% 19% 36% 25% 2	564
	21st to end	Night	16% 6% 27% 29% 20% 2	730
September	1st to 10th	Night	15% 9% 30% 27% 17% 3	760
	11th to 20th	Night	16% 7% 23% 29% 21% 5%	760
	21st to end	Night	23% 10% 21% 27% 16% 3	760
October	1st to 10th	Night	22% 12% 29% 22% 14% 1	760
	11th to 20th	Night	30% 15% 28% 19% 8% 1	760
	21st to end	Night	32% 16% 29% 19% 4	836
November	1st to 10th	Night	29% 13% 28% 23% 7%	780
	11th to 20th	Night	27% 16% 35% 16% 6% 1	800
	21st to end	Night	33% 16% 28% 19% 4	800
December	1st to 10th	Night	33% 19% 30% 13% 4	800
	11th to 20th	Night	27% 20% 35% 15% 3 1	800
	21st to end	Night	33% 18% 30% 16% 3	880

Page generated at 2025-02-22 06:51:35. Version ac07

Copyright © 2025 Attilla Danko.