Terre Haute
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Terre Haute 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	14% 8% 3 7% 5% 4 4 4 5% 7% 38%	108291
	Night	15% 9% 3 7% 4 4 4 3 5% 6% 39%	110102
Transparency	Day	43% 5% 11% 24% 15% 2	111911
	Night	45% 4 11% 22% 16% 2	114610
Seeing	Day	16% 10% 26% 25% 17% 7%	15891
	Night	18% 8% 28% 31% 14% 1	25842

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	15% 13% 7% 12% 6% 4 4 3 5% 6% 26%	3617
	11th to 20th	Day	12% 13% 6% 14% 8% 7% 5% 4 4 5% 21%	3620
	21st to end	Day	22% 15% 5% 9% 4 4 3 3 3 4 28%	4209
February	1st to 10th	Day	17% 12% 5% 8% 6% 3 3 3 5% 6% 31%	1933
	11th to 20th	Day	17% 10% 4 11% 5% 5% 4 3 5% 6% 32%	1848
	21st to end	Day	18% 12% 3 8% 5% 4 4 4 4 6% 34%	1570
March	1st to 10th	Day	20% 17% 3 8% 4 3 3 2 3 3 33%	3120
	11th to 20th	Day	13% 9% 3 5% 4 3 4 3 4 7% 44%	3256
	21st to end	Day	15% 9% 4 8% 5% 5% 5% 4 6% 7% 31%	4148
April	1st to 10th	Day	16% 11% 2 6% 4 3 4 3 5% 8% 37%	2280
	11th to 20th	Day	17% 8% 2 6% 4 4 4 4 6% 5% 40%	2254
	21st to end	Day	20% 8% 3 7% 5% 4 4 3 5% 7% 36%	2363
May	1st to 10th	Day	18% 8% 3 8% 5% 4 5% 4 6% 9% 30%	4082
	11th to 20th	Day	19% 7% 2 6% 4 4 4 4 4 7% 38%	4081
	21st to end	Day	10% 6% 2 7% 4 5% 5% 5% 7% 8% 42%	4730
June	1st to 10th	Day	11% 5% 2 6% 4 3 4 5% 6% 9% 44%	2660
	11th to 20th	Day	8% 4 2 4 4 4 5% 5% 6% 9% 48%	2660
	21st to end	Day	10% 5% 2 6% 4 5% 5% 4 7% 9% 43%	2660
July	1st to 10th	Day	13% 6% 2 6% 4 4 5% 4 6% 10% 40%	4440
	11th to 20th	Day	6% 4 2 6% 4 5% 5% 5% 8% 10% 45%	4440
	21st to end	Day	11% 6% 2 7% 5% 5% 6% 5% 8% 10% 35%	4813
August	1st to 10th	Day	7% 4 2 5% 4 4 4 4 6% 10% 51%	4053
	11th to 20th	Day	9% 5% 2 6% 5% 5% 5% 5% 8% 10% 41%	3729
	21st to end	Day	5% 5% 2 5% 4 4 4 3 6% 10% 53%	4180
September	1st to 10th	Day	11% 5% 3 5% 5% 4 5% 4 5% 7% 47%	2280
	11th to 20th	Day	9% 4 2 5% 4 4 5% 5% 7% 8% 48%	2115
	21st to end	Day	12% 4 2 6% 4 4 4 3 5% 7% 50%	2090
October	1st to 10th	Day	13% 3 2 5% 4 4 3 3 5% 6% 52%	2090
	11th to 20th	Day	15% 5% 2 7% 4 4 3 3 5% 6% 45%	1925
	21st to end	Day	20% 7% 2 7% 5% 4 4 3 4 5% 40%	1881
November	1st to 10th	Day	11% 6% 2 5% 4 4 4 3 5% 7% 51%	1762
	11th to 20th	Day	18% 10% 2 7% 4 3 3 3 4 6% 41%	1800
	21st to end	Day	18% 10% 3 7% 4 4 3 3 4 5% 38%	1800
December	1st to 10th	Day	13% 10% 3 8% 4 4 4 2 4 4 44%	2812
	11th to 20th	Day	16% 14% 5% 9% 5% 4 5% 3 4 6% 28%	3008
	21st to end	Day	30% 16% 6% 10% 5% 4 3 3 4 4 17%	3982
January	1st to 10th	Night	17% 14% 8% 11% 4 4 4 3 4 6% 26%	6348
	11th to 20th	Night	15% 18% 5% 10% 6% 6% 5% 3 3 4 24%	6360
	21st to end	Night	21% 12% 5% 8% 6% 4 3 3 4 5% 29%	6766
February	1st to 10th	Night	20% 12% 4 9% 5% 4 3 4 4 5% 30%	2356
	11th to 20th	Night	15% 10% 3 9% 5% 4 4 3 5% 6% 35%	2218
	21st to end	Night	20% 11% 4 7% 4 3 3 3 5% 5% 35%	1884
March	1st to 10th	Night	21% 16% 3 6% 4 3 3 3 4 5% 33%	3733
	11th to 20th	Night	14% 7% 2 5% 4 4 3 3 4 6% 48%	3690
	21st to end	Night	18% 7% 3 8% 5% 4 3 4 5% 6% 37%	3512
April	1st to 10th	Night	15% 8% 3 6% 4 4 5% 3 5% 7% 41%	1900
	11th to 20th	Night	17% 7% 3 5% 3 3 4 3 4 7% 43%	1875
	21st to end	Night	17% 8% 2 7% 5% 5% 5% 5% 6% 5% 36%	1815
May	1st to 10th	Night	17% 10% 3 7% 5% 5% 4 3 6% 8% 32%	2813
	11th to 20th	Night	18% 6% 2 6% 4 4 4 3 5% 7% 42%	2812
	21st to end	Night	11% 5% 2 6% 4 5% 5% 4 6% 9% 43%	2818
June	1st to 10th	Night	10% 6% 3 5% 4 4 4 3 5% 7% 50%	1520
	11th to 20th	Night	8% 5% 2 5% 4 4 5% 2 6% 8% 52%	1520
	21st to end	Night	7% 5% 2 5% 4 4 4 4 8% 11% 45%	1520
July	1st to 10th	Night	11% 5% 2 6% 3 3 4 2 6% 9% 49%	2530
	11th to 20th	Night	5% 3 2 4 3 3 5% 4 7% 9% 54%	2530
	21st to end	Night	8% 7% 3 8% 5% 4 5% 4 5% 11% 40%	2750
August	1st to 10th	Night	7% 5% 2 4 3 3 4 4 5% 9% 54%	2869
	11th to 20th	Night	6% 4 2 6% 4 4 4 4 6% 8% 51%	3100
	21st to end	Night	6% 3 1 4 3 4 4 3 6% 8% 57%	3476
September	1st to 10th	Night	11% 5% 2 5% 4 3 4 3 5% 6% 51%	1900
	11th to 20th	Night	7% 4 2 4 4 3 3 3 5% 8% 58%	2044
	21st to end	Night	13% 6% 2 5% 4 3 4 3 5% 7% 48%	2090
October	1st to 10th	Night	8% 4 2 6% 3 3 4 4 5% 6% 57%	2090
	11th to 20th	Night	16% 6% 2 4 2 3 3 3 4 6% 51%	2248
	21st to end	Night	17% 8% 2 5% 4 4 4 3 5% 7% 41%	2717
November	1st to 10th	Night	11% 7% 2 5% 4 4 4 3 4 5% 51%	2536
	11th to 20th	Night	13% 9% 3 6% 4 3 4 4 4 7% 44%	2600
	21st to end	Night	21% 10% 4 6% 4 4 3 2 4 6% 36%	2600
December	1st to 10th	Night	16% 10% 3 8% 4 3 3 2 4 4 43%	4367
	11th to 20th	Night	18% 11% 3 9% 5% 5% 4 3 4 5% 33%	5199
	21st to end	Night	30% 16% 5% 8% 4 4 3 3 3 5% 19%	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	59% 4 7% 21% 7% 1	3618
	11th to 20th	Day	66% 3 10% 10% 9% 2	3620
	21st to end	Day	63% 2 7% 19% 6% 2	4209
February	1st to 10th	Day	54% 4 12% 19% 9% 2	1933
	11th to 20th	Day	52% 5% 11% 22% 9% 1	1858
	21st to end	Day	53% 5% 9% 22% 9% 2	1570
March	1st to 10th	Day	56% 4 7% 18% 12% 2	3120
	11th to 20th	Day	39% 5% 12% 28% 15% 1	3256
	21st to end	Day	49% 8% 13% 24% 6% 1	4148
April	1st to 10th	Day	45% 6% 12% 22% 14% 1	2280
	11th to 20th	Day	44% 6% 9% 25% 12% 4	2254
	21st to end	Day	48% 5% 11% 22% 10% 3	2363
May	1st to 10th	Day	47% 9% 14% 23% 7%	4120
	11th to 20th	Day	45% 6% 11% 27% 10%	4085
	21st to end	Day	37% 8% 12% 20% 20% 3	4743
June	1st to 10th	Day	34% 8% 13% 25% 16% 4	2660
	11th to 20th	Day	31% 8% 13% 23% 22% 4	2660
	21st to end	Day	35% 9% 16% 20% 17% 4	2660
July	1st to 10th	Day	40% 5% 11% 27% 14% 2	4371
	11th to 20th	Day	32% 6% 13% 30% 17% 1	4365
	21st to end	Day	42% 5% 17% 20% 14% 2	4662
August	1st to 10th	Day	30% 5% 15% 32% 16% 1	4039
	11th to 20th	Day	36% 6% 14% 28% 15% 1	3765
	21st to end	Day	28% 4 16% 32% 15% 4	4179
September	1st to 10th	Day	36% 6% 10% 25% 18% 4	2280
	11th to 20th	Day	30% 8% 11% 25% 23% 3	2115
	21st to end	Day	33% 6% 10% 24% 24% 3	2090
October	1st to 10th	Day	22% 3 7% 28% 36% 3	3480
	11th to 20th	Day	29% 3 8% 26% 32% 1	3166
	21st to end	Day	39% 2 8% 25% 25% 1	3081
November	1st to 10th	Day	34% 4 13% 27% 17% 5%	1762
	11th to 20th	Day	45% 4 9% 22% 16% 4	1800
	21st to end	Day	50% 4 9% 22% 14% 1	1800
December	1st to 10th	Day	45% 3 11% 28% 12%	2812
	11th to 20th	Day	59% 3 10% 22% 6% 1	3005
	21st to end	Day	73% 3 10% 10% 4	3982
January	1st to 10th	Night	60% 4 9% 19% 7%	6348
	11th to 20th	Night	65% 3 8% 12% 9% 3	6360
	21st to end	Night	58% 3 8% 21% 9% 1	6766
February	1st to 10th	Night	56% 5% 13% 17% 8% 1	2356
	11th to 20th	Night	50% 4 11% 20% 13% 2	2219
	21st to end	Night	52% 4 10% 21% 11% 2	1884
March	1st to 10th	Night	54% 4 8% 22% 10% 1	3733
	11th to 20th	Night	36% 5% 10% 25% 22% 1	3690
	21st to end	Night	46% 6% 11% 28% 7% 1	3512
April	1st to 10th	Night	42% 6% 10% 25% 15% 2	1900
	11th to 20th	Night	41% 5% 9% 22% 17% 5%	1875
	21st to end	Night	47% 7% 10% 20% 13% 3	1815
May	1st to 10th	Night	48% 8% 14% 22% 7%	2840
	11th to 20th	Night	42% 6% 13% 26% 12% 1	2813
	21st to end	Night	36% 9% 12% 20% 18% 4	2826
June	1st to 10th	Night	34% 6% 10% 25% 22% 4	1520
	11th to 20th	Night	31% 6% 11% 24% 22% 6%	1520
	21st to end	Night	29% 8% 17% 21% 20% 6%	1520
July	1st to 10th	Night	34% 6% 11% 25% 20% 4	2490
	11th to 20th	Night	26% 4 13% 31% 24% 2	2482
	21st to end	Night	41% 4 17% 21% 15% 3	2662
August	1st to 10th	Night	28% 5% 15% 37% 14% 2	2859
	11th to 20th	Night	31% 5% 15% 28% 20% 2	3130
	21st to end	Night	26% 4 14% 30% 22% 4	3476
September	1st to 10th	Night	32% 5% 10% 26% 20% 6%	1900
	11th to 20th	Night	26% 4 10% 27% 27% 5%	2044
	21st to end	Night	35% 5% 10% 22% 23% 5%	2090
October	1st to 10th	Night	20% 4 6% 23% 44% 3	3480
	11th to 20th	Night	25% 2 8% 26% 36% 2	3733
	21st to end	Night	35% 3 8% 25% 25% 5%	4467
November	1st to 10th	Night	35% 5% 9% 26% 21% 5%	2536
	11th to 20th	Night	41% 4 10% 24% 18% 3	2600
	21st to end	Night	51% 3 10% 23% 13% 1	2600
December	1st to 10th	Night	47% 3 11% 26% 13%	4367
	11th to 20th	Night	55% 3 12% 19% 11%	5201
	21st to end	Night	70% 3 10% 12% 4 1	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	24% 19% 32% 17% 7% 1	300
	11th to 20th	Day	25% 17% 37% 17% 4	300
	21st to end	Day	24% 22% 33% 18% 4	330
February	1st to 10th	Day	27% 18% 34% 17% 4	285
	11th to 20th	Day	25% 20% 34% 15% 5% 1	270
	21st to end	Day	30% 13% 40% 14% 3	225
March	1st to 10th	Day	21% 21% 38% 16% 4	270
	11th to 20th	Day	28% 18% 34% 16% 5%	327
	21st to end	Day	28% 16% 32% 17% 7%	506
April	1st to 10th	Day	20% 17% 32% 23% 7% 1	460
	11th to 20th	Day	19% 17% 27% 23% 12% 2	452
	21st to end	Day	22% 15% 34% 18% 9% 2	460
May	1st to 10th	Day	20% 12% 30% 25% 10% 3	463
	11th to 20th	Day	19% 8% 28% 25% 15% 6%	487
	21st to end	Day	10% 5% 29% 26% 20% 10%	679
June	1st to 10th	Day	12% 5% 22% 32% 23% 6%	680
	11th to 20th	Day	10% 5% 22% 33% 23% 7%	680
	21st to end	Day	12% 5% 28% 27% 21% 8%	680
July	1st to 10th	Day	11% 4 14% 27% 24% 19%	671
	11th to 20th	Day	6% 3 18% 32% 28% 13%	668
	21st to end	Day	11% 2 14% 30% 32% 11%	739
August	1st to 10th	Day	10% 1 13% 29% 31% 16%	488
	11th to 20th	Day	15% 2 15% 32% 27% 10%	479
	21st to end	Day	5% 3 11% 32% 34% 16%	539
September	1st to 10th	Day	10% 4 15% 29% 31% 10%	490
	11th to 20th	Day	9% 2 11% 31% 30% 18%	490
	21st to end	Day	14% 7% 23% 22% 22% 12%	490
October	1st to 10th	Day	11% 4 25% 32% 21% 8%	490
	11th to 20th	Day	15% 15% 31% 21% 14% 4	333
	21st to end	Day	23% 18% 32% 20% 6%	330
November	1st to 10th	Day	14% 14% 35% 23% 13% 2	300
	11th to 20th	Day	22% 16% 32% 18% 10% 2	300
	21st to end	Day	22% 14% 35% 21% 8%	300
December	1st to 10th	Day	16% 21% 38% 17% 7% 2	300
	11th to 20th	Day	24% 14% 35% 20% 6% 1	300
	21st to end	Day	36% 13% 30% 16% 5%	330
January	1st to 10th	Night	22% 13% 34% 27% 4	1000
	11th to 20th	Night	25% 14% 36% 21% 4	1000
	21st to end	Night	23% 13% 37% 25% 3	1100
February	1st to 10th	Night	26% 11% 36% 25% 2	796
	11th to 20th	Night	22% 14% 37% 24% 3	743
	21st to end	Night	26% 11% 37% 23% 3	628
March	1st to 10th	Night	22% 14% 35% 26% 4	760
	11th to 20th	Night	21% 12% 35% 26% 5%	760
	21st to end	Night	25% 7% 32% 30% 6%	660
April	1st to 10th	Night	17% 12% 33% 33% 5%	570
	11th to 20th	Night	20% 12% 27% 29% 12%	563
	21st to end	Night	19% 9% 36% 28% 6% 1	570
May	1st to 10th	Night	18% 7% 31% 33% 11%	570
	11th to 20th	Night	15% 5% 26% 35% 18% 1	561
	21st to end	Night	10% 3 22% 39% 24% 2	617
June	1st to 10th	Night	10% 5% 19% 43% 22% 1	570
	11th to 20th	Night	10% 2 21% 44% 23% 1	570
	21st to end	Night	8% 1 22% 41% 27% 1	570
July	1st to 10th	Night	9% 2 12% 32% 38% 7%	555
	11th to 20th	Night	6% 3 14% 39% 34% 4	552
	21st to end	Night	6% 2 13% 44% 32% 3	624
August	1st to 10th	Night	9% 2 9% 40% 38% 3	567
	11th to 20th	Night	7% 2 12% 41% 34% 4	564
	21st to end	Night	8% 1 11% 34% 40% 5%	627
September	1st to 10th	Night	11% 3 14% 38% 30% 5%	570
	11th to 20th	Night	7% 3 15% 35% 36% 4	714
	21st to end	Night	15% 5% 19% 32% 24% 4	760
October	1st to 10th	Night	9% 6% 22% 37% 22% 4	760
	11th to 20th	Night	19% 10% 27% 28% 16% 1	760
	21st to end	Night	21% 10% 32% 28% 8%	836
November	1st to 10th	Night	15% 7% 33% 32% 13%	780
	11th to 20th	Night	18% 12% 32% 29% 9%	800
	21st to end	Night	25% 11% 30% 26% 7%	800
December	1st to 10th	Night	23% 10% 37% 25% 5%	865
	11th to 20th	Night	25% 9% 34% 25% 7% 1	1000
	21st to end	Night	30% 14% 30% 22% 3	1100

Page generated at 2025-02-03 03:05:56. Version ac07

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