Mactaquac Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mactaquac Provincial Park clear sky chart from 2005-11-06 to 2026-05-17.

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	19% 10% 3 8% 5% 4 4 4 5% 7% 32%	131649
	Night	18% 10% 3 7% 5% 4 4 4 5% 6% 33%	131261
Transparency	Day	51% 5% 11% 21% 11% 1	135148
	Night	50% 5% 11% 21% 11% 1	135850
Seeing	Day	28% 16% 30% 18% 7% 1	18211
	Night	26% 14% 30% 23% 6%	26243

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	13% 16% 6% 12% 6% 6% 4 3 4 5% 25%	4093
	11th to 20th	Day	15% 13% 5% 15% 7% 5% 4 2 4 4 27%	4610
	21st to end	Day	8% 9% 3 8% 5% 5% 5% 5% 7% 9% 35%	5440
February	1st to 10th	Day	14% 11% 5% 9% 7% 6% 4 4 5% 7% 30%	1890
	11th to 20th	Day	16% 12% 3 9% 6% 5% 5% 4 5% 6% 30%	1843
	21st to end	Day	11% 14% 3 9% 5% 4 4 4 6% 6% 34%	1702
March	1st to 10th	Day	25% 13% 4 9% 5% 3 3 3 4 5% 27%	4781
	11th to 20th	Day	20% 14% 4 9% 5% 5% 4 3 5% 5% 26%	5090
	21st to end	Day	26% 12% 4 8% 4 4 4 3 5% 7% 22%	5587
April	1st to 10th	Day	22% 15% 3 7% 4 4 4 3 4 5% 29%	2470
	11th to 20th	Day	21% 11% 3 7% 4 4 4 3 5% 7% 33%	2702
	21st to end	Day	25% 9% 3 6% 3 4 4 3 4 5% 32%	2730
May	1st to 10th	Day	25% 12% 3 8% 5% 4 5% 4 5% 5% 24%	6016
	11th to 20th	Day	26% 8% 2 7% 5% 4 4 3 5% 6% 29%	6228
	21st to end	Day	21% 9% 3 7% 5% 4 5% 4 6% 7% 30%	7259
June	1st to 10th	Day	25% 9% 3 8% 4 4 4 4 5% 7% 28%	3000
	11th to 20th	Day	21% 7% 3 6% 5% 3 4 3 5% 7% 35%	3000
	21st to end	Day	27% 9% 3 6% 4 4 4 4 5% 6% 28%	3000
July	1st to 10th	Day	16% 7% 3 7% 6% 6% 6% 4 8% 9% 28%	6820
	11th to 20th	Day	15% 7% 2 6% 4 5% 5% 4 6% 8% 38%	6758
	21st to end	Day	13% 7% 2 6% 5% 4 5% 4 6% 8% 40%	6681
August	1st to 10th	Day	18% 8% 2 7% 5% 5% 5% 4 5% 7% 34%	4235
	11th to 20th	Day	14% 7% 3 9% 6% 5% 5% 5% 6% 7% 32%	4175
	21st to end	Day	15% 5% 2 6% 4 4 4 4 6% 8% 43%	4675
September	1st to 10th	Day	13% 5% 2 5% 4 4 5% 4 5% 8% 46%	2376
	11th to 20th	Day	16% 5% 2 6% 4 3 4 3 4 5% 48%	2200
	21st to end	Day	18% 6% 2 7% 4 3 4 3 4 6% 43%	2200
October	1st to 10th	Day	18% 8% 2 6% 4 4 4 3 5% 6% 41%	2052
	11th to 20th	Day	20% 8% 2 6% 4 4 4 3 5% 7% 36%	2000
	21st to end	Day	21% 10% 3 8% 5% 4 5% 3 4 5% 31%	2045
November	1st to 10th	Day	20% 9% 3 7% 4 4 3 3 5% 7% 35%	1802
	11th to 20th	Day	21% 8% 2 6% 4 4 5% 3 5% 8% 33%	1680
	21st to end	Day	21% 12% 4 9% 4 4 5% 3 4 6% 29%	1680
December	1st to 10th	Day	20% 11% 3 7% 3 3 4 4 5% 7% 32%	2588
	11th to 20th	Day	22% 10% 3 8% 5% 5% 3 2 4 5% 34%	2688
	21st to end	Day	19% 12% 4 7% 4 4 4 3 4 5% 33%	3553
January	1st to 10th	Night	14% 15% 5% 10% 6% 5% 4 4 5% 6% 26%	8831
	11th to 20th	Night	18% 13% 5% 12% 6% 5% 4 3 5% 6% 25%	8258
	21st to end	Night	8% 11% 4 8% 6% 5% 5% 4 6% 7% 37%	8727
February	1st to 10th	Night	14% 12% 4 8% 5% 4 4 4 5% 6% 33%	2730
	11th to 20th	Night	15% 13% 4 8% 6% 5% 5% 4 6% 6% 29%	2663
	21st to end	Night	15% 13% 2 7% 5% 6% 4 4 5% 5% 34%	2102
March	1st to 10th	Night	24% 13% 5% 9% 5% 5% 4 3 3 4 26%	5265
	11th to 20th	Night	20% 12% 4 7% 4 4 5% 4 6% 8% 27%	5089
	21st to end	Night	30% 10% 3 6% 4 3 3 3 5% 5% 28%	5587
April	1st to 10th	Night	24% 12% 2 6% 5% 4 4 3 4 5% 30%	2146
	11th to 20th	Night	24% 9% 2 6% 4 4 4 3 4 5% 35%	1868
	21st to end	Night	24% 9% 3 6% 4 4 4 3 5% 7% 31%	1890
May	1st to 10th	Night	25% 9% 3 8% 5% 5% 4 4 5% 5% 27%	4144
	11th to 20th	Night	23% 7% 3 6% 5% 4 5% 4 5% 6% 33%	3809
	21st to end	Night	19% 8% 3 7% 4 4 4 4 6% 7% 35%	3679
June	1st to 10th	Night	24% 8% 2 6% 5% 5% 6% 3 5% 7% 30%	1400
	11th to 20th	Night	19% 7% 2 6% 5% 3 4 5% 6% 7% 36%	1400
	21st to end	Night	26% 7% 2 7% 4 4 4 4 5% 7% 32%	1400
July	1st to 10th	Night	15% 7% 2 7% 5% 5% 6% 5% 7% 7% 32%	3160
	11th to 20th	Night	16% 7% 2 7% 5% 5% 4 4 6% 9% 35%	3203
	21st to end	Night	11% 6% 2 7% 5% 5% 5% 5% 7% 8% 41%	4124
August	1st to 10th	Night	18% 6% 3 8% 5% 5% 5% 4 6% 8% 32%	2915
	11th to 20th	Night	12% 7% 3 8% 5% 5% 5% 5% 6% 9% 36%	2872
	21st to end	Night	14% 5% 2 5% 3 4 4 4 5% 6% 46%	3223
September	1st to 10th	Night	15% 5% 2 6% 4 3 4 4 6% 7% 46%	2020
	11th to 20th	Night	15% 6% 2 5% 4 3 3 3 4 5% 49%	2200
	21st to end	Night	18% 6% 1 5% 4 4 3 3 4 6% 45%	2200
October	1st to 10th	Night	19% 7% 2 5% 3 3 3 3 5% 6% 44%	2347
	11th to 20th	Night	18% 9% 2 7% 5% 4 4 4 4 7% 38%	2400
	21st to end	Night	22% 9% 3 7% 4 4 4 3 5% 6% 33%	2790
November	1st to 10th	Night	21% 7% 3 7% 5% 4 3 3 4 6% 36%	2714
	11th to 20th	Night	20% 7% 3 7% 5% 5% 4 4 5% 5% 35%	2940
	21st to end	Night	22% 11% 3 6% 5% 4 4 3 6% 6% 30%	2940
December	1st to 10th	Night	17% 11% 3 8% 5% 4 4 3 5% 6% 33%	4817
	11th to 20th	Night	22% 10% 2 6% 4 4 4 3 5% 5% 34%	5741
	21st to end	Night	20% 13% 4 9% 4 4 4 3 4 4 32%	7667

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	60% 4 12% 15% 9%	4094
	11th to 20th	Day	60% 5% 10% 16% 8% 1	4640
	21st to end	Day	42% 5% 9% 24% 18% 1	5440
February	1st to 10th	Day	54% 5% 11% 19% 9% 2	1890
	11th to 20th	Day	55% 4 10% 19% 10% 1	1851
	21st to end	Day	49% 4 11% 22% 11% 2	1702
March	1st to 10th	Day	61% 3 8% 12% 13% 3	4785
	11th to 20th	Day	59% 5% 12% 14% 7% 2	5090
	21st to end	Day	62% 3 6% 18% 10% 2	5587
April	1st to 10th	Day	57% 4 9% 14% 14% 2	2470
	11th to 20th	Day	52% 4 11% 21% 12% 1	2702
	21st to end	Day	53% 5% 8% 16% 13% 5%	2730
May	1st to 10th	Day	60% 6% 7% 17% 9% 1	6027
	11th to 20th	Day	55% 6% 10% 19% 7% 2	6232
	21st to end	Day	53% 6% 10% 17% 14%	7259
June	1st to 10th	Day	56% 6% 10% 17% 11% 1	3000
	11th to 20th	Day	48% 5% 11% 20% 14% 1	3000
	21st to end	Day	57% 7% 9% 17% 10% 1	3000
July	1st to 10th	Day	49% 7% 15% 20% 9%	6745
	11th to 20th	Day	42% 7% 15% 27% 10%	6677
	21st to end	Day	41% 6% 12% 30% 9% 1	6489
August	1st to 10th	Day	51% 5% 12% 25% 6%	4222
	11th to 20th	Day	48% 7% 14% 23% 8%	4214
	21st to end	Day	38% 6% 13% 27% 16% 1	4675
September	1st to 10th	Day	37% 6% 13% 28% 15%	2376
	11th to 20th	Day	40% 4 10% 29% 17% 2	2200
	21st to end	Day	42% 5% 9% 27% 17% 1	2200
October	1st to 10th	Day	48% 5% 11% 27% 9%	3338
	11th to 20th	Day	45% 5% 12% 29% 9%	3240
	21st to end	Day	42% 4 15% 22% 16%	3282
November	1st to 10th	Day	51% 4 12% 20% 12% 1	1802
	11th to 20th	Day	49% 5% 14% 18% 13% 2	1680
	21st to end	Day	56% 5% 13% 19% 6%	1680
December	1st to 10th	Day	50% 5% 18% 17% 9%	2588
	11th to 20th	Day	54% 4 9% 18% 10% 4	2688
	21st to end	Day	53% 4 11% 16% 12% 3	3553
January	1st to 10th	Night	57% 4 12% 18% 8%	8831
	11th to 20th	Night	59% 6% 9% 18% 8% 1	8303
	21st to end	Night	44% 5% 8% 23% 18% 2	8727
February	1st to 10th	Night	51% 5% 11% 19% 12% 1	2730
	11th to 20th	Night	53% 5% 11% 19% 11% 2	2666
	21st to end	Night	52% 4 9% 20% 12% 2	2102
March	1st to 10th	Night	63% 4 5% 14% 11% 3	5274
	11th to 20th	Night	54% 6% 17% 14% 8% 1	5090
	21st to end	Night	59% 2 6% 19% 12% 1	5587
April	1st to 10th	Night	57% 4 8% 15% 11% 4	2146
	11th to 20th	Night	52% 3 9% 19% 15% 2	1868
	21st to end	Night	53% 5% 9% 17% 14% 3	1890
May	1st to 10th	Night	56% 7% 10% 16% 10% 1	4150
	11th to 20th	Night	51% 6% 11% 22% 7% 2	3810
	21st to end	Night	47% 7% 15% 21% 9% 2	3680
June	1st to 10th	Night	54% 6% 10% 19% 9% 1	1400
	11th to 20th	Night	47% 5% 12% 23% 11% 1	1400
	21st to end	Night	54% 6% 10% 20% 10% 1	1400
July	1st to 10th	Night	49% 6% 14% 22% 8%	3125
	11th to 20th	Night	45% 8% 15% 27% 5%	3161
	21st to end	Night	39% 9% 14% 27% 10%	4002
August	1st to 10th	Night	51% 8% 12% 22% 7%	2903
	11th to 20th	Night	43% 10% 18% 23% 7%	2899
	21st to end	Night	36% 7% 16% 24% 16% 2	3223
September	1st to 10th	Night	38% 5% 12% 29% 14% 1	2020
	11th to 20th	Night	38% 4 12% 29% 16% 1	2200
	21st to end	Night	41% 6% 9% 28% 15% 1	2200
October	1st to 10th	Night	46% 4 11% 25% 13%	3841
	11th to 20th	Night	41% 5% 12% 28% 14%	3899
	21st to end	Night	44% 5% 15% 23% 13%	4503
November	1st to 10th	Night	49% 5% 13% 22% 10% 1	2714
	11th to 20th	Night	50% 5% 12% 20% 11% 1	2940
	21st to end	Night	54% 6% 13% 16% 10% 1	2940
December	1st to 10th	Night	50% 5% 13% 24% 7%	4817
	11th to 20th	Night	51% 3 11% 21% 13% 1	5742
	21st to end	Night	55% 4 9% 18% 10% 3	7667

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	32% 17% 35% 14% 2	220
	11th to 20th	Day	35% 23% 28% 10% 4	220
	21st to end	Day	24% 22% 33% 16% 4 1	351
February	1st to 10th	Day	29% 17% 32% 16% 6% 1	430
	11th to 20th	Day	30% 23% 29% 13% 4 1	426
	21st to end	Day	27% 24% 30% 17% 3	432
March	1st to 10th	Day	33% 22% 31% 10% 3	540
	11th to 20th	Day	33% 20% 30% 12% 4 1	540
	21st to end	Day	37% 20% 27% 10% 5% 1	594
April	1st to 10th	Day	42% 22% 24% 10% 2	540
	11th to 20th	Day	36% 21% 28% 11% 3 1	532
	21st to end	Day	33% 19% 30% 13% 4 1	540
May	1st to 10th	Day	36% 17% 29% 13% 4 1	543
	11th to 20th	Day	32% 16% 28% 16% 6% 1	671
	21st to end	Day	28% 16% 34% 15% 7%	790
June	1st to 10th	Day	33% 15% 28% 17% 6% 1	730
	11th to 20th	Day	29% 14% 27% 22% 7% 1	730
	21st to end	Day	30% 12% 30% 19% 7% 1	730
July	1st to 10th	Day	23% 12% 34% 19% 10% 1	720
	11th to 20th	Day	20% 9% 33% 25% 11% 2	695
	21st to end	Day	17% 10% 39% 26% 7% 2	576
August	1st to 10th	Day	18% 10% 34% 24% 11% 2	526
	11th to 20th	Day	18% 12% 24% 30% 14% 3	519
	21st to end	Day	21% 12% 27% 26% 11% 3	583
September	1st to 10th	Day	13% 15% 33% 24% 10% 3	530
	11th to 20th	Day	23% 11% 28% 23% 12% 4	530
	21st to end	Day	22% 15% 29% 20% 10% 4	530
October	1st to 10th	Day	23% 15% 23% 25% 11% 3	447
	11th to 20th	Day	26% 17% 29% 16% 10% 3	420
	21st to end	Day	31% 18% 29% 16% 6%	462
November	1st to 10th	Day	32% 16% 28% 18% 5% 1	425
	11th to 20th	Day	34% 19% 26% 15% 6%	430
	21st to end	Day	35% 19% 27% 16% 3	430
December	1st to 10th	Day	34% 16% 28% 17% 4	367
	11th to 20th	Day	40% 23% 26% 10% 1	220
	21st to end	Day	32% 24% 27% 14% 3	242
January	1st to 10th	Night	28% 19% 30% 20% 3	950
	11th to 20th	Night	31% 16% 29% 21% 4	845
	21st to end	Night	21% 21% 35% 19% 4	924
February	1st to 10th	Night	24% 20% 32% 19% 4	840
	11th to 20th	Night	27% 21% 32% 16% 3	823
	21st to end	Night	26% 18% 32% 22% 3	692
March	1st to 10th	Night	28% 19% 32% 19% 2	840
	11th to 20th	Night	26% 17% 33% 19% 5%	840
	21st to end	Night	29% 15% 32% 19% 5%	924
April	1st to 10th	Night	36% 16% 29% 16% 2	760
	11th to 20th	Night	32% 16% 31% 17% 5%	624
	21st to end	Night	32% 12% 31% 19% 6%	630
May	1st to 10th	Night	28% 15% 30% 23% 4	630
	11th to 20th	Night	32% 12% 32% 19% 5%	611
	21st to end	Night	22% 14% 35% 25% 4	536
June	1st to 10th	Night	28% 8% 31% 27% 6%	400
	11th to 20th	Night	21% 10% 29% 32% 6% 1	400
	21st to end	Night	30% 7% 28% 31% 6%	400
July	1st to 10th	Night	19% 7% 36% 30% 8%	390
	11th to 20th	Night	18% 5% 28% 37% 12%	388
	21st to end	Night	20% 7% 30% 34% 9%	521
August	1st to 10th	Night	19% 4 26% 38% 12%	598
	11th to 20th	Night	18% 6% 28% 34% 13%	592
	21st to end	Night	16% 8% 30% 30% 15% 1	660
September	1st to 10th	Night	18% 9% 35% 27% 10% 1	655
	11th to 20th	Night	19% 9% 25% 32% 14% 2	800
	21st to end	Night	21% 12% 28% 28% 11% 1	800
October	1st to 10th	Night	22% 10% 29% 28% 10% 1	800
	11th to 20th	Night	22% 13% 29% 25% 10% 1	800
	21st to end	Night	29% 15% 29% 22% 5%	880
November	1st to 10th	Night	29% 15% 28% 22% 5% 1	845
	11th to 20th	Night	30% 16% 28% 19% 7% 1	950
	21st to end	Night	31% 17% 27% 20% 4	950
December	1st to 10th	Night	33% 14% 29% 19% 4	950
	11th to 20th	Night	32% 20% 28% 16% 3	950
	21st to end	Night	32% 19% 27% 18% 3	1045

Page generated at 2026-05-14 02:58:58. Version ac07

Copyright © 2026 Attilla Danko.