Free Astrology Tool

Sky Weather Calculator

Astrolium's sky weather calculator lists upcoming aspects, sign ingresses, and retrograde stations for any moment. Free, 30-day lookahead, no signup.

Sky weather
What is about to happen in the sky — applying aspects, ingresses, stations.
Lookahead14 days
1d30d

What is Sky Weather?

Sky weather is the practical version of "what is the sky doing right now." Cast a chart for any moment and any place, and the engine returns the calendar of upcoming aspects between the seven traditional planets, the sign changes those planets are about to make, and the dates when any of them will turn retrograde or direct. The seven planets are the working set because they are the ones whose aspects perfect inside a human planning horizon — outer-planet aspects take years.

Astrolium's sky weather calculator returns applying aspects, separating aspects, sign ingresses, and planetary stations for any moment and place. Inputs are a date, time, location, and a 1–30 day lookahead window; the engine scans the seven traditional planets (Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn) for every Ptolemaic aspect that will perfect inside the window, every ingress where a planet crosses into the next sign, and every station where a planet turns retrograde or direct. Each row reports the exact UTC moment, applying or separating direction, orb in degrees, and a one-line read on what the contact means. The seven-planet set is deliberate: outer-planet aspects take years and do not fit a human planning horizon. Math runs on Swiss Ephemeris, accurate to under 1 arc second. Practitioners use it for horary, electional, transit-watching, and pre-session prep. Free, no account required.

When practitioners reach for this

The horary astrologer needs to know whether the Moon will perfect to its target before changing sign. The electional astrologer wants the calendar of inner-planet ingresses for the next two weeks before picking a date. The transit watcher wants to know when Mars stations, because the station week is the loudest one. The reading prep before a session benefits from a single-screen picture of what is happening overhead, so the client's transits land inside the right context. Sky weather is the one read for all four cases.

How to read each section

Applying aspects come first. The list is sorted by degrees_to_perfection, smallest first, so the next event in the sky is at the top. Each row tells you which planet is applying, which planet is being approached, the aspect type with its glyph, the current orb, the rough days-to-perfection estimate, and the sign where the aspect perfects. The Moon dominates this list because the Moon moves about 13 degrees per day; anything Moon-related at the top of the list is happening today or tomorrow.

Separating aspects are the same shape, with the smallest orbs first. A separating aspect is one that already perfected and is now widening. Read this list to see what just happened, which is often as useful as knowing what is coming — the Moon separating from Mars is the residue of yesterday's mood, the Sun separating from a square is the relief after the tension peaked.

Ingresses and stations

Sign ingresses are the moments when a planet leaves one sign and enters the next. They reset the planet's dignity, its rulerships, and the houses it triggers in any natal chart. Mercury into Gemini is loud for thinkers and writers. Venus into Cancer is loud for the mood of relationships. The ingress list shows the planet, the sign it is leaving, the sign it is entering, the degrees-to-ingress, and the rough days estimate.

Stations are the moments when a planet's apparent speed crosses zero — turning retrograde, then later turning direct again. The Sun and Moon never station, so they are excluded. Mercury stations are most frequent, three times a year for about three weeks each. Mars stations every two-plus years for ten weeks. The station week itself is the loudest part of the cycle, because the planet appears to stop in one degree of the zodiac for several days, intensifying the sign and house it occupies.

What sky weather is not

Sky weather is not a transit report. A transit report tells you which transiting planet is making which aspect to your natal chart. Sky weather tells you what the transiting planets are doing to each other. The two read differently and the two answer different questions. If you want personal timing, use the transit report calculator. If you want the shared sky calendar, you are in the right place.

Sky weather is also not horary. Horary picks one chart, the chart for the question, and reads it in detail with significators and considerations. Sky weather aggregates many small events into one calendar. The horary astrologer uses sky weather as background context; the horary judgment itself comes from the horary astrology calculator.

Pairing sky weather with electional work

The natural companion for sky weather is electional. The electional astrology calculator scores a date range for a specific activity and returns the best windows. Sky weather tells you why those windows are good — which planet is about to ingress, which aspect is about to perfect, which station is coming up. Run them side-by-side when planning a wedding, a business launch, or any decision that benefits from a chosen moment rather than an inherited one.

Related

Frequently asked questions

What does the sky weather calculator return?
Four lists for the lookahead window you choose. Applying aspects between the seven traditional planets, sorted by how soon they perfect. Separating aspects, sorted by orb. Sign ingresses, with the planet, the sign it is leaving, and the sign it is entering. Retrograde and direct stations, with the planet and the rough date. Use it when you want a single-screen picture of what the sky is doing next, without casting a chart for a specific person.
How does an applying aspect differ from a transit to my chart?
An applying aspect is between two transiting planets, not between a transit and a natal point. Saturn applying to a sextile with Jupiter is a sky event that everyone shares for the days it stays inside orb. A Saturn transit to your natal Sun is personal, only you have it. Sky weather shows the first kind. The transit report calculator shows the second.
Why use the horary engine for non-horary work?
The horary aspects endpoint is the API surface that returns the future-aspect calendar in one call. It is named after horary because horary timing needs that exact data — when does the Moon next perfect to its dispositor, when does Venus enter the next sign, when does Mercury station. Outside horary, the same data is useful for electional planning, transit watching, and any moment where you want to know the order of upcoming events in the sky.
How accurate are the perfect-in dates?
The API returns degrees_to_perfection along each planet's actual path. We translate that into a days estimate using mean speeds for each planet — that is accurate to within a few hours for the Moon and within a day or two for the slow planets. Use the days estimate to scan the calendar. For minute-precision timing on a specific aspect, cast the chart at the suspected perfection moment and confirm by orb.
What is the lookahead slider for?
It controls how far ahead the engine searches. Set to 1-3 days for a tight focus on the Moon's next contacts. Set to 14 days for a balanced two-week view that catches inner-planet ingresses. Set to 30 days for the full month, which also picks up Mars and Venus station events when they are coming. The 30-day cap matches the horary tradition of judging a chart within its natural radius.

Want this inside your client roster?

Run the calculator above for a one-off chart, or save every chart you cast to a client profile in Astrolium.