Carranza Field
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Carranza Field clear sky chart from 2005-11-05 to 2018-02-14.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
37%
15729
21%
48804
12%
15698
48%
15698
25%
30500

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
27%
779
22%
2716
10%
776
43%
776
21%
1649
January16th to endNight
24%
832
22%
2757
8%
832
42%
832
23%
1684
February1st to 15thNight
19%
760
18%
2405
6%
757
35%
757
21%
1515
February16th to endNight
21%
631
26%
1893
10%
631
42%
631
24%
1162
March1st to 15thNight
25%
720
21%
2125
10%
720
39%
720
26%
1331
March16th to endNight
27%
768
21%
2010
9%
768
37%
768
26%
1364
April1st to 15thNight
25%
718
18%
1796
5%
718
32%
718
28%
1196
April16th to endNight
35%
720
19%
1800
7%
720
40%
720
29%
1215
May1st to 15thNight
32%
533
17%
1613
8%
533
39%
533
21%
1092
May16th to endNight
47%
374
15%
1497
12%
374
54%
374
18%
936
June1st to 15thNight
49%
360
15%
1440
15%
360
56%
360
20%
895
June16th to endNight
57%
360
16%
1440
19%
360
63%
360
26%
808
July1st to 15thNight
58%
340
12%
1360
17%
340
59%
340
20%
835
July16th to endNight
65%
379
16%
1421
17%
357
71%
357
26%
792
August1st to 15thNight
63%
614
18%
1684
13%
611
65%
611
34%
1039
August16th to endNight
62%
764
18%
1910
10%
764
63%
764
35%
1247
September1st to 15thNight
54%
720
24%
1800
14%
720
58%
720
36%
1161
September16th to endNight
56%
717
27%
1957
22%
717
60%
717
33%
1231
October1st to 15thNight
46%
720
22%
2125
18%
720
53%
720
28%
1322
October16th to endNight
37%
768
28%
2364
17%
768
53%
768
32%
1389
November1st to 15thNight
37%
760
23%
2472
14%
760
50%
760
26%
1489
November16th to endNight
33%
780
23%
2577
14%
780
46%
780
23%
1585
December1st to 15thNight
26%
780
17%
2730
7%
780
40%
780
18%
1755
December16th to endNight
22%
832
21%
2912
7%
832
40%
832
20%
1808

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 ForecastData
Points
Cloud CoverDay
15%5%245%2445%7%41%
49274
Night
15%5%2442445%7%43%
48975
Cloud CoverDay
14%5%2443445%7%41%
49283
Night
15%5%2442445%7%43%
48981
TransparencyDay
41%411%23%16%2
48963
Night
40%411%23%17%3
48804
SeeingDay
18%8%26%25%15%5%
6243
Night
18%8%28%31%11%1
15731

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
13%5%35%435%445%44%
1552
16th to endDay
16%6%2342335%6%44%
1817
February1st to 15thDay
16%6%35%32445%6%41%
1755
16th to endDay
13%7%36%5%335%5%5%41%
1580
March1st to 15thDay
16%6%15%5%3445%6%41%
1823
16th to endDay
19%5%34424445%42%
2214
April1st to 15thDay
17%6%24324347%43%
2152
16th to endDay
15%42442446%8%42%
2160
May1st to 15thDay
18%5%245%3435%7%38%
2348
16th to endDay
15%5%245%3446%7%40%
2618
June1st to 15thDay
13%5%35%5%35%5%5%8%37%
2520
16th to endDay
10%425%5%36%6%6%9%38%
2520
July1st to 15thDay
9%6%35%6%36%5%6%9%36%
2520
16th to endDay
8%425%6%37%7%7%10%34%
2649
August1st to 15thDay
11%5%25%6%25%46%8%39%
2253
16th to endDay
13%4245%25%5%7%9%39%
2292
September1st to 15thDay
13%5%1443445%6%46%
2160
16th to endDay
14%6%25%5%24447%40%
2001
October1st to 15thDay
18%6%24422446%43%
1833
16th to endDay
16%423323337%49%
1858
November1st to 15thDay
18%5%24422346%44%
1716
16th to endDay
15%424334345%48%
1709
December1st to 15thDay
17%5%35%424446%42%
1560
16th to endDay
20%6%3441345%6%39%
1664
January1st to 15thNight
17%5%2442335%6%43%
2716
16th to endNight
17%6%24324446%43%
2757
February1st to 15thNight
15%7%3442435%6%41%
2404
16th to endNight
16%5%14423445%46%
1893
March1st to 15thNight
18%5%15%323347%45%
2112
16th to endNight
18%6%3442333445%
2010
April1st to 15thNight
16%6%24324345%45%
1796
16th to endNight
16%5%2442445%7%42%
1800
May1st to 15thNight
19%7%25%424447%36%
1613
16th to endNight
16%6%25%4345%47%39%
1495
June1st to 15thNight
14%6%25%426%5%47%39%
1440
16th to endNight
7%4345%35%5%6%9%43%
1440
July1st to 15thNight
9%6%26%5%346%6%11%37%
1440
16th to endNight
6%4245%46%5%7%11%42%
1517
August1st to 15thNight
7%5%25%5%35%45%8%46%
1695
16th to endNight
10%6%25%4345%6%7%44%
1910
September1st to 15thNight
13%5%235%23438%47%
1800
16th to endNight
13%6%23423348%47%
1957
October1st to 15thNight
17%5%23423346%46%
2125
16th to endNight
15%5%12323336%51%
2364
November1st to 15thNight
15%6%25%313345%47%
2472
16th to endNight
14%6%25%5%2445%6%42%
2577
December1st to 15thNight
19%5%35%42445%6%37%
2730
16th to endNight
17%6%35%42445%6%40%
2912

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
13%5%25%435%346%44%
1552
16th to endDay
17%6%15%324345%44%
1817
February1st to 15thDay
16%7%25%324446%41%
1755
16th to endDay
13%7%36%5%3445%6%40%
1580
March1st to 15thDay
16%5%245%3435%6%41%
1833
16th to endDay
18%5%24423346%42%
2213
April1st to 15thDay
17%6%34323346%43%
2152
16th to endDay
15%4343245%5%7%42%
2160
May1st to 15thDay
18%5%245%245%47%39%
2348
16th to endDay
15%5%244345%5%7%40%
2618
June1st to 15thDay
13%6%25%5%35%5%5%8%37%
2520
16th to endDay
10%4246%46%6%7%8%39%
2520
July1st to 15thDay
9%5%35%6%36%5%6%8%37%
2520
16th to endDay
8%5%25%6%46%6%8%9%34%
2649
August1st to 15thDay
11%5%25%6%346%5%8%39%
2253
16th to endDay
11%5%24435%5%7%8%40%
2292
September1st to 15thDay
11%5%1443435%7%45%
2160
16th to endDay
15%6%26%5%24447%40%
2001
October1st to 15thDay
18%5%14423346%43%
1833
16th to endDay
16%423223336%49%
1858
November1st to 15thDay
17%5%24422337%44%
1716
16th to endDay
15%324424446%48%
1709
December1st to 15thDay
16%5%25%424446%42%
1560
16th to endDay
20%6%24423446%40%
1664
January1st to 15thNight
17%5%2432335%6%43%
2716
16th to endNight
17%6%2432445%6%43%
2757
February1st to 15thNight
15%8%2443345%6%41%
2397
16th to endNight
16%424424445%46%
1893
March1st to 15thNight
18%5%24422347%45%
2125
16th to endNight
18%6%3442432444%
2010
April1st to 15thNight
16%6%24424335%44%
1796
16th to endNight
17%4245%2445%6%42%
1800
May1st to 15thNight
19%6%35%424448%36%
1613
16th to endNight
16%7%25%424447%39%
1495
June1st to 15thNight
14%5%35%5%25%447%40%
1440
16th to endNight
7%425%5%35%6%6%10%42%
1440
July1st to 15thNight
8%5%26%5%45%6%5%11%36%
1440
16th to endNight
6%4346%46%47%10%42%
1517
August1st to 15thNight
7%5%25%43445%8%46%
1695
16th to endNight
11%425%5%345%6%7%43%
1910
September1st to 15thNight
13%5%14423447%47%
1800
16th to endNight
13%6%2432445%7%46%
1957
October1st to 15thNight
17%5%24323446%45%
2125
16th to endNight
15%5%13323345%50%
2364
November1st to 15thNight
15%5%25%323445%47%
2472
16th to endNight
14%6%2442445%6%42%
2577
December1st to 15thNight
19%5%35%5%2445%6%37%
2730
16th to endNight
17%6%2442435%6%40%
2912

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
41%313%22%14%5%
1553
16th to endDay
41%210%26%15%3
1817
February1st to 15thDay
43%410%24%14%2
1758
16th to endDay
44%39%26%13%2
1580
March1st to 15thDay
43%313%23%13%2
1833
16th to endDay
42%38%23%17%3
2214
April1st to 15thDay
41%310%24%14%5%
2152
16th to endDay
39%410%19%22%4
2160
May1st to 15thDay
43%411%22%15%2
2348
16th to endDay
40%6%14%24%12%1
2622
June1st to 15thDay
43%6%13%23%11%1
2520
16th to endDay
39%7%13%22%15%2
2520
July1st to 15thDay
42%5%10%24%14%2
2371
16th to endDay
39%7%12%26%11%2
2482
August1st to 15thDay
39%6%13%23%16%1
2240
16th to endDay
37%5%13%21%18%3
2292
September1st to 15thDay
36%412%21%22%2
2160
16th to endDay
44%36%20%23%2
2001
October1st to 15thDay
41%311%23%18%2
1833
16th to endDay
37%28%26%21%2
1858
November1st to 15thDay
41%211%24%17%2
1716
16th to endDay
37%39%28%18%2
1709
December1st to 15thDay
42%315%22%13%2
1560
16th to endDay
45%315%21%13%1
1664
January1st to 15thNight
41%310%22%17%4
2716
16th to endNight
41%310%27%16%1
2757
February1st to 15thNight
43%212%23%14%3
2405
16th to endNight
38%39%24%19%4
1893
March1st to 15thNight
40%312%23%16%3
2125
16th to endNight
45%29%20%18%4
2010
April1st to 15thNight
41%210%22%17%4
1796
16th to endNight
41%49%18%22%3
1800
May1st to 15thNight
47%48%20%16%2
1613
16th to endNight
44%5%13%17%15%2
1497
June1st to 15thNight
43%6%11%20%17%
1440
16th to endNight
35%5%15%24%16%2
1440
July1st to 15thNight
41%7%15%20%13%2
1360
16th to endNight
33%7%17%27%12%1
1421
August1st to 15thNight
34%5%14%23%20%1
1684
16th to endNight
37%413%20%20%2
1910
September1st to 15thNight
36%411%23%21%2
1800
16th to endNight
36%46%25%24%2
1957
October1st to 15thNight
39%411%24%17%3
2125
16th to endNight
35%39%28%20%3
2364
November1st to 15thNight
38%310%22%18%6%
2472
16th to endNight
41%310%23%17%3
2577
December1st to 15thNight
47%312%21%12%1
2730
16th to endNight
43%313%24%13%2
2912

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
16%20%38%14%7%2
90
16th to endDay
25%15%35%20%3
131
February1st to 15thDay
22%21%38%16%1
191
16th to endDay
16%19%38%22%3
239
March1st to 15thDay
21%13%31%26%6%
270
16th to endDay
21%13%34%22%43
288
April1st to 15thDay
24%9%34%20%9%2
270
16th to endDay
20%6%31%22%13%4
270
May1st to 15thDay
28%14%26%15%12%3
288
16th to endDay
21%320%30%18%5%
331
June1st to 15thDay
17%6%24%28%17%5%
315
16th to endDay
14%426%32%15%6%
315
July1st to 15thDay
16%317%32%23%6%
305
16th to endDay
11%216%33%27%9%
326
August1st to 15thDay
14%18%31%23%10%
313
16th to endDay
11%13%31%26%15%
332
September1st to 15thDay
12%5%25%23%18%15%
315
16th to endDay
19%221%27%15%12%
314
October1st to 15thDay
24%416%29%18%6%
315
16th to endDay
15%8%30%23%18%2
320
November1st to 15thDay
20%8%27%27%14%1
280
16th to endDay
17%12%36%17%13%2
239
December1st to 15thDay
24%15%33%13%11%2
90
16th to endDay
34%8%38%17%1
96
January1st to 15thNight
20%14%32%27%5%
780
16th to endNight
22%11%37%25%2
832
February1st to 15thNight
20%15%38%24%1
760
16th to endNight
20%16%37%23%2
631
March1st to 15thNight
23%11%35%24%4
720
16th to endNight
21%9%35%24%7%1
768
April1st to 15thNight
19%12%38%24%5%
718
16th to endNight
19%6%33%32%7%
720
May1st to 15thNight
22%7%33%27%8%
533
16th to endNight
19%320%39%16%
375
June1st to 15thNight
17%321%41%15%
360
16th to endNight
8%221%48%18%
360
July1st to 15thNight
12%116%49%19%
340
16th to endNight
8%114%46%25%2
379
August1st to 15thNight
9%212%47%25%2
614
16th to endNight
13%113%39%28%3
764
September1st to 15thNight
16%218%37%21%3
720
16th to endNight
18%314%34%25%3
717
October1st to 15thNight
20%5%21%31%18%2
720
16th to endNight
17%8%32%28%11%
768
November1st to 15thNight
18%9%29%28%12%1
760
16th to endNight
17%10%30%29%9%1
780
December1st to 15thNight
23%9%32%23%9%1
780
16th to endNight
19%12%38%24%3
832
Page generated at 2018-02-15 10:58:46. Version ac04

Copyright 2018 A. Danko


Carranza Field Clear Sky Chart |Charts Home